we had a few 70's les pauls in the shop i used to work in and also some brand new custom shop reissue type ones. the quality is so variable.
that headstock inlay is seriously shoddy, which points to Gibson, probably more likely to be recent Gibson.
It would be interesting to know of the fretboard binding covers the ends of the frets. If it does, it's likely to be a Gibbo, if not, it may have had work done, or is a copy. Those tuners aren't 70's.
I've seen Gibsons made of loads of little pieces of wood, the solid finish ones were ridiculous. Being able to have a look when the paint was removed from one of the 70's models, i saw the whitest mahogany ever. i.e. it wasn't even mahogany.
If it's a 70's Gibson, beyond reasonable doubt, then don't let it go for anything less than $2500. I'd probably say £2500 tbh, which is like > $5000 atm.