Les Pauls have set necks and I’d be surprised if the neck came from a different body. It’s possible but it seems unlikely. It’s easy to believe various parts such as tuners, pickups, switches, bridges, saddles and knobs could have originated on different guitars. It was increasingly common in the 70s for tuners on older guitars to be upgraded to Grovers and Schallers. Bridges sometimes collapse after long use. Pickups would sometimes begin to falter from night after night of sweat drenched live performances thereby requiring replacement. Sometimes they were just replaced for other reasons. I recall the #3 started life as a Les Paul Deluxe with mini-humbuckers before getting routed out to fit the humbuckers.
