Hi again Horace,
A minor point, one that has no bearing on your hunt but helps your understanding of the Villiers numbering system.
Villiers didn't allot a three figure identifier to each manufacturer and leave it at that. They allotted the number to each individual contract with a manufacturer and when the manufacturer came back for another lot of engines for next years range for example, Villiers gave the new contract a new three figure number so you get different identifiers from year to year.
Of course Villiers rapidly ran out of numbers as they got up to 999 by about 1950 or so. They then started again adding an A suffix so you can get a 765A or 765B identifier neither of which bears any relationship to your engine. When that ran out they went to a B suffix and so on. They were up to an F suffix by the time they went bust. Its lots of fun working through the Villiers maze.
Motorcycle engines were only part of Villiers business. They used the same numbering system with engines supplied for industrial, agricultural and horticultural use, so there are great gaps in the motorcycle numbers. So far no one has come up with a master list although people are trying.
It'll make life a little easier when they do.
Cheers,