now i think about it, that rings a bell.. as i had a book in the early 70s when i was a nipper which took on all journeys to spot where cars originate...albeit it was for post '63 ("A" Suffix") registrations...
a new car is issued an age related (to use your definition)
if you transfer a VEM off a vehicle, DVLA issue a replacement specific to the ageof the car.
If your Hillman was on a G plate, and you transferred that VRM to either retention or another vehicle, DVLA will issue a replacement G VRM...
If the car cranks for reasonable time it is unlikely to be the battery and the jump leads to another battery won’t h
as others have posted it is possible an EIS or crank sensor issue
first step is to check if you have both a spark and fuel delivery
If the garage has quoted for recoding
12V BATTERY TO BE REPLACED THEN CODING OF :
ENGINE CONTROL UNIT
POWER ELECTRICS CONTROL UNIT
AC CONTROL UNIT
ESP CONTROL UNIT
FUEL PUMP CONTROL UNIT
Can the RAC do this ?