Thank you all, thats very interesting! I didn't expect a unanimous verdict.
For me there appear to be pros and cons both ways. The 2003 car has everything the other one has as well as the addition of heated seats, which I think are really welcome in the winter. But I think it might have a few more scuffs as well as miles. But it's not without history. The owner does everything whether he needs to or not, e.g. he recently changed all the bakes all round even though they were still good for a bit, and changed front and back suspension, new vacuum hose for the engine, etc. Just no info on the SBC. Plus the garage is close to me and I've dealt with them before and they are honest.
The 2005 car has fewer miles and has both front ball joints done, as well as the service history stated above including new SBC in 2012. But beyond that I don't really know if it's going to be trouble-free or not. Plus it don't have the heated seats and is a private sale far out of town. Here's the MOT History if it makes a difference. Neither have been without their issues:
Registration number: OY05PXP
Vehicle make MERCEDES
Vehicle model E 320
Date first used 23 March 2005
Fuel type Diesel
Colour Silver
*
MOT history of this vehicle
Test date 1 April 2015
Expiry date 31 March 2016
Test Result Pass
Odometer reading 115,459 miles
MOT test number 2064 3199 5016
Test date 26 March 2015
Test Result Fail
Odometer reading 115,459 miles
MOT test number 1278 6528 5442
Reason(s) for failure
Exhaust system not adequately supported (7.1.1)
Offside Front suspension has excessive play in a lower suspension ball joint (2.5.B.1a)
Nearside Front suspension has excessive play in a lower suspension ball joint (2.5.B.1a)
Test date 19 March 2014
Expiry date 28 March 2015
Test Result Pass
Odometer reading 102,238 miles
MOT test number 2253 0897 4060
Advisory notice item(s)
Offside Track rod end ball joint has slight play (2.2.B.1f)
Nearside Rear Brake pipe slightly corroded (3.6.B.2c)
Offside Rear Brake pipe slightly corroded (3.6.B.2c)
Rear exhaust bracketts corroded not supporting exhaust
near side rear sub frame bush,(front) starting to seep oil
Test date 28 March 2013
Expiry date 28 March 2014
Test Result Pass
Odometer reading 93,784 miles
MOT test number 6375 1778 3041
Advisory notice item(s)
Offside Front Suspension arm has slight play in a ball joint (2.4.G.2)
rear exhaust box reinforcement corroded, offside centre exhaust bracket corroded
Test date 28 March 2012
Expiry date 28 March 2013
Test Result Pass
Odometer reading 81,429 miles
MOT test number 7564 3828 2063
Advisory notice item(s)
Nearside Front Tyre worn close to the legal limit (4.1.E.1)
Offside Front Tyre worn close to the legal limit (4.1.E.1)
rear exhaust sections corroded
wiper blades smear
front registration plate damaged
Engine malfunction warning light is on
Test date 29 March 2011
Expiry date 28 March 2012
Test Result Pass
MOT test number 1471 3838 1417
Advisory notice item(s)
Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)
Nearside Side repeater damaged, but still visible from a reasonable distance (1.4.A.2e)
Offside Rear position lamp(s) damaged, but still visible from a reasonable distance (1.1.A.3d)
Front registration plate slight damage
Slight play nearside inner rack ball joint
Test date 29 March 2011
Test Result Fail
MOT test number 5276 6828 1050
Reason(s) for failure
Offside Headlamp aim too high (1.8)
Advisory notice item(s)
Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)
Nearside Side repeater damaged, but still visible from a reasonable distance (1.4.A.2e)
Offside Rear position lamp(s) damaged, but still visible from a reasonable distance (1.1.A.3d)
Front registration plate slight damage
Slight play nearside inner rack ball joint
Test date 25 March 2010
Expiry date 26 March 2011
Test Result Pass
MOT test number 5112 3408 0068
Advisory notice item(s)
Front Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)
Protective boot for nearside rear air suspension unit adrift.
Test date 25 March 2010
Test Result Fail
MOT test number 1044 0458 0073
Reason(s) for failure
Offside Front position lamp(s) not working (1.1.A.3b)
Nearside Front Brake pad(s) less than 1.5 mm thick (3.5.1g)
Advisory notice item(s)
Front Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)
Front brake disc worn, pitted or scored, but not seriously weakened (3.5.1i)
Protective boot for nearside rear air suspension unit adrift.
Test date 27 March 2009
Expiry date 26 March 2010
Test Result Pass
MOT test number 1322 7648 9411
Advisory notice item(s)
Front Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)
Cover for nearside rear air suspension unit adrift.
Test date 28 July 2008
Expiry date 27 July 2009
Test Result Pass
MOT test number 5941 9041 8216
Advisory notice item(s)
Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
Test date 25 July 2008
Test Result Fail
MOT test number 6144 2700 8244
Reason(s) for failure
Offside Rear Tyre tread depth below requirements of 1.6mm (4.1.E.1)
Front registration plate character(s) laid out in an incorrect format (6.3.4f)
Rear registration plate character(s) laid out in an incorrect format (6.3.4f)
Advisory notice item(s)
Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
-----
And the 2003 car:
Registration number: OJZ6954
*
Vehicle make MERCEDES
Vehicle model E 320
Date first used 31 December 2003
Fuel type Diesel
Colour Silver
*
MOT history of this vehicle
Test date 17 January 2015
Expiry date 13 February 2016
Test Result Pass
Odometer reading 148,248 miles
MOT test number 3099 6711 5032
Advisory notice item(s)
Under-trays fitted obscuring some underside components
Engine covers fitted obscuring some components in the engine bay
Child seat fitted
Test date 28 January 2014
Expiry date 13 February 2015
Test Result Pass
Odometer reading 225,312 miles
MOT test number 3573 1842 4045
Advisory notice item(s)
Front Front suspension has slight play in a lower suspension ball joint (2.5.B.1a)
Rear Subframe mounting prescribed area is corroded but not considered excessive (2.4.A.3)
Rear Brake hose slightly deteriorated (3.6.B.4d)
Test date 29 January 2013
Expiry date 13 February 2014
Test Result Pass
Odometer reading 129,841 miles
MOT test number 6784 7902 3024
Advisory notice item(s)
Offside Obligatory mirror deteriorated, but not seriously affecting the rear view (8.1.2a)
Test date 14 February 2012
Expiry date 13 February 2013
Test Result Pass
Odometer reading 117,190 miles
MOT test number 8496 8584 2011
Test date 14 February 2012
Test Result Fail
Odometer reading 117,190 miles
MOT test number 3895 1524 2005
Reason(s) for failure
Offside Front Brake pipe excessively corroded (3.6.B.2c)
Offside Lower Ball joint has excessive play (2.2.B.1f)
Test date 26 January 2011
Expiry date 25 January 2012
Test Result Pass
MOT test number 5856 2612 1002
Advisory notice item(s)
Tyre worn close to the legal limit (4.1.E.1)
Offside Front Brake pipe slightly corroded (3.6.B.2c)
Offside Upper Ball joint has slight play (2.2.B.1f)
Test date 25 January 2011
Test Result Fail
MOT test number 5899 5592 1001
Reason(s) for failure
Nearside Track rod end ball joint has excessive play (2.2.B.1f)
Front Brake pad(s) less than 1.5 mm thick (3.5.1g)
Advisory notice item(s)
Tyre worn close to the legal limit (4.1.E.1)
Offside Front Brake pipe slightly corroded (3.6.B.2c)
Offside Upper Ball joint has slight play (2.2.B.1f)
Test date 15 August 2009
Expiry date 14 August 2010
Test Result Pass
MOT test number 6909 5722 9265
Test date 14 August 2009
Test Result Fail
MOT test number 9341 0612 9234
Reason(s) for failure
Front registration plate background overprinted or shadowed with text (6.3.1e)
Rear registration plate background overprinted or shadowed with text (6.3.1e)
Offside Front Upper Suspension arm has excessive play in a ball joint (2.4.G.2)
Advisory notice item(s)
Windscreen has damage to an area less than a 40mm circle outside zone 'A' (8.3.1d)