Regstration number or v5 from engine / frame number

Is it possible to find the registration number from the engine / frame number ?
I have what I believe to be a 1967 160 Monza Junior with engine number 27486 - DM160 but have mislaid the info I got when I bought it some years ago. Its a resto project and the reg number on the rear mudguard comes up as a 1984 model. I have looked at the .gov site and in order to use a V62 form to get a replacement V5 requires the reg number.
Does the club have any records of engine/frame numbers and reg numbers ?
many thanks pab

Morning, we do not have a registration of engine and frame numbers, we can provide dating certificates which in turn allow a reg number to be issued by DVLA, all details and application are on club website

Thanks Martyn. Could you tell me where the frame number is located on a 160 monza junior as I have been unable to find one. Thanks pab