Luna line Vin numbers...

Ive not found much around the web with correct info, so just wanted to check here.

my Cometa has the frame as 22/8 and engine as 75S (not 75SL as I have seen around - although most of it is hidden under the bracket for the oil pump).

my Lui frame is 20/9*576xxx but the engine is j50*577xxx

is it correct for Lui to have j50 prefix?

also, should I check under the bracket on the Cometa to see if 75S is correct? the other US Cometa i know of the owner also reports just 75S.

thanks!
Gene

just had a look at 2 cometa cases both are 75s, italian imports to the uk , dont know the history on these 2 engines