Motor itself looks funny, not one instantly recognizable to me. Looks like a drum brake on the left side of it. Its kind of cool, with that moped or small motorcycle front end, and the moped wheel in back. Looks like he got the headset angle a bit steep though.
But yeah, its likely a 500w rated motor similar to those in the current 48v 1000w kits. If the flange is fairly narrow where the spokes attach, like 30mm or so, then its a 500w motor. If its 35mm or more, then its a real motorcycle power motor.
Where I live, you'd get about 3 bucks for each of the old sla's at the place that would buy the metal in the frame for about 1 buck.
What this thing needs though, would be a better frame, with a swing arm for those shocks, a 72v controller, and then some lipos.
On the other hand, it could be fun to save it intact, for some museum in 100 years.