i think someone else asked this and i advised them to maybe try renault in dunstable? i could dig out some details if you want... i'm sure martin's right aswell about the rootes club access to the old files.
i was hoping my van was pre-72, since it was ex-raf, reg'd '77, but manufacture was aug 76, so the way things stand no luck. nice to know your vehicle's d.o.b. tho!