Looks like a partsmaster to me.
Body looks "mid 60's" neck is late 60's/early 70's
I'd even dare to say that the whole body, including pick ups, trem, etc.. is mid 60's and the neck is a later addition.
A lot of Jazzmasters had their necks robbed when the vintage strat crazy came allong. Or the guitar simply recieved a new neck for whatever reasons)
Defenitly a refin (normally the part where the paint stick sat at the factory is not painted)
Trem is an original (post 62) Pat. Pend. nr. (yes same as AVRI, but the chrome is thicker and the "trem lock" buttom has the same chrome shine as the rest, not the case on the AVRI unit where the button apears more with a mat shine)
Seriously, al the above aside. If you like the guitar and it ticks all the right boxes and the price is right, then (consider) buy(ing) it.
Even if it's a Partsmaster. I've seen quiet some originals (good and bad, going for quiet some cash) but I honnestly take a good playing and sounding Partsmaster made from vintage parts over a dead sounding original. (Yes, not all Fender guitars where made by fairies or pixies. Some duds are out there as well...)
Imho, that's the beauty of Leo's thinking, if it's broken, change the neck, the body, etc....
Financially, this guitar will be cheaper (since it's not a factory original) so you can get it refinned by a pro and set up to your taste... And up up with a killer Vintage Jm for less money...
just saying