Got it thanks! I found both codes. Looks like it is a 428cc engine from 1968 based on the 9792968 code and the date code G038. Am I missing something or is that right? I am not sure since there seem to be a lot of potential redundancies and overlaps with these engine codes. Not a very well thought out plan it seems (like you said, YH could be any one of 5 different engines).
