That crusty little micro-tank is of a CB160 or similar. That is a distinctly Honda gas valve. I used a crusty little micro tank on my Savage, again with a distinctly Honda gas valve, I think one from a CMX250C.
Here's my tank:
Before...

Installed...

I love the look of cafe bikes, but can't ride them. Bad back won't let me bend like that anymore. So, I put the apes on mine. Same era, different style. The heyday of biking had to be the 1960s...
-WD