You never know unless you x-ray.
That is the grim reality of it. The internet has taught fraudsters how to build better and better bogus guitars. We tell them that the lacquer and plastics have to glow under UV light, so you can bet that they have been working on this. I think one of the reasons I don't get excited about vintage guitars is the whole thing about having to be worried about any hairline crack you can find, or the notion that some part might have been swapped out.
To be fair, the headstock on that Les Paul would cause me some concerns. I'm not sure the finish would unevenly sink into the areas around the inlays like that. It suggests, to me, that the headstock was sanded and some of the filler around the inlay pieces was sanded out. Some rattle-can nitro was then oversprayed and, being rattle-can nitro, the solvents gassed off and what was left shrunk into the recesses left by the missing filler. The light, blobby serial number and general swirly nature of the lacquer on the back of the headstock is also troubling. The open-book shape on the back of the headstock has lost some of its definition and symmetry and it looks like the lacquer built a slight meniscus towards the edge of the headstock.
