Ask to see all
receipts for the "rebuild".
If it is really a 68, the engine numbers will be between DU66246 to DU85903.
At least it is right shift, so it just might be a 68...
The only reason it will be 750cc and not 650cc is if someone has put a big bore kit on it.
The reason I doubt anything written there is all the Harley crap on the bike, in nearly every case I have talked to someone with a similar Harley crossover build they have been a dickhead and wouldn't know their arse from their elbow.
Oh gawd, it even has tassels.
Example, he didn't even have the sense to prop up the broken kick start for the photos.
Go prepared. I can still see there is a very good base to work off for a decent bobber build though.
Good luck learning to right shift too!