That was something I learned along the way - that MB continued with fluid couplings rather than TCs - hence an extra ratio in the box over rival's efforts.
My W123 had a 4sp auto but I don't know if it was FC or TC. Does anyone know the transition date?
Auto could suit the car. Especially if the gearchange is as recalcitrant as I imagine it to be.
Many of the older M-B manual boxes were actually quite nice , certainly back in the Ponton and Fintail era , although most were column change , the gearboxes were lovely in terms of the gear change , tactile and easy to use ; my W115 220/8 was also column change and I loved driving that . I also used to get shots of a friend's 230SL Pagoda and the floor change 4 speed manual in that car was pleasant to use too . One very common thing with all the old M-B manuals , though , was the choice of ratios with an incredibly low first which ran out barely after you got moving , and widely spaced ratios up to a very tall top .
My W114 280E was the very rare 5 speed manual with the Getrag box ; by this time ( 1975 car ) the gear change had a rubbery feel as opposed to the feeling of something well oiled and superbly engineered as the earlier ones . That 5 speed box was supposedly a close ratio one , but it felt more like a 4 speed plus overdrive top to me - it was , in its day , a very fast car and , being in my early 20's when I had it , I drove it like a hooligan much of the time : these still being my formative years behind the wheel
That brings me onto another subject . As I have mentioned before , I learned to drive and passed my test in my dad's 220/8 , then was given the car when he replaced it with a new W123 250 . Having driven all of these extensively , and spent my early years 'hooning around' in these cars , I can tell you that the W115 with the four cylinder engine was a much better balanced and better handling car ! Even on ( IIRC 165 or 175 SR14's ) it was eminently 'chuckable' , could easily be put into four wheel drifts and recovered , had , for the time , amazing levels of road holding ( a friend at the time with an Alfasud could not believe how I could throw it round corners without losing grip or complaint from the tyres ) ; that W115 had taut , firm suspension , while still comfortable which made it one of the best cars I ever had the pleasure of owning . By contrast the W114 280E , with the big , heavy lump in the front was something of a barge in comparison , never so eager to change direction quickly and only by virtue of having the manual box and substantially more power , with which you could either power it through corners , or kick the back end out at will , could it be hustled quickly along roads ( what with my driving style back then I went through countless tyres , remember burning through a set of Pirelli 185/70x14 CN36's in only five thousand or so miles ! , countless sets of brake pads although , oddly , don't remember changing discs often , and three clutches durning my tenure from 48,000 miles to 272,000 miles in that car , by which time it still went like a rocket but the body was rusting away underneath me and I sold it for spares to go over to the Ponton as my daily driver ; my dad had passed away by this time and the W123 had been sold ) . Incidentally , the 6 cyl Ponton could be made to pick up its skirts and be hustled along , but it did teach me to learn and respect swing axles
That W123 , by comparison with either of the earlier cars , was even more of a barge , with wallowy soft suspension , the six cylinder 250 having the weight and thirst penalties of the 280E but without any of the go . I did eventually have all three variants of 280 in the W123 chassis E/CE/TE , all autos and all barge like again ; the autos never felt anywhere close to as fast as that manual W114 280E I had , but memory over a few years can play tricks .
Anyway , the point of all this rambling is that I'm wondering if another vuable option might be to look for a W124 230E/CE/TE donor car and transplant the 4 cyl engine and gearbox from that - it would probably go about as well as the older 250 , be better on fuel , should be easy to drop in and would lighten the front end to give noticeably better handling . While there are , of course , newer and more powerful 4 cyl engines , the associated electronics would be a PITA to transplant , but the M102 shouldn't be too bad - it just wouldn't look 'period' in there . As previously mentioned , you could keep the original engine so that a future owner coukd go back if desired .
with the existing technology-- but running. 
Having done a rough costing on the carburettor option+ electronic distributer at around £1300 [ despite its simplicity appeal ] Mega squirt begins to look a very attractive [and possibly cheaper?] alternative. It's only then I would turn to autoboxes, differentials and V8 conversions.
