I've never seen a 64 thumb rest so far down. Wonder if it and the pickguard are original ? Or maybe it had none and the owner screwed one on?
Yeah, looks like someone bought it to learn bass in the 60s and gave up. But having it sit under a bed for 50 years with flat wounds and a bowed neck could have boogered the neck beyond just a simple adjust,net to dial it back in. So, even if there is no neck break, it still seems like a crap shoot.
Definitely would need to see it in person IMO.