Anyone know what these are from or what they fit?

 

They're not 62-64 panhead tanks as the emblems might indicate and the emblems could be repop with stick on mounts.. The fuel petcock bung on the left tank seems shovel to me. Need to see more pictures, more angles.

 

Shovel tanks probably repops and badly done aftermarket badges.
You can kinda get an idea if they are aftermarket, factory tanks are lighter than most aftermarket one, heavier gauge steel used.

 

show us how they mount on the backbone. Get a pick of the tanks from the top sides

 

I see where yer going...Thinking maybe Slab sides...but I think No based on forward mount, tho cannot see the mount under dash either.....But...Correct that we should See to Know..

 

Look at the holes on the tab's, evo tanks had the bigger hole with a thin washer tack welded on for rubber grommets, those aren't flat sides, can tell they're repops by where the cross over tube is, too high up.

 

Never underestimate the Chiwanese MFG

 

some keener eyes here than mine! I learned something new today thanks!

 

No my friend, it just comes from long experience dealing with this kind of junk. Never touched a set of aftermarket tanks I didn't have to modify or get a little violent with to fit right.