I think they are all gens, but every 1 has issues. Each watch has some component or components that appear to be either aftermarket, swapped from a different gen model or modified in some way.
That said, while $100 grand is alot of cash, it may be a good deal if you price each watch individually. The way I see it, he could probably get another $20k by parting the collection out. So, if you look at it that way, it is a bargain. Still, you would not end up with 100% correct examples, which I am sure is why the seller is offering them as a package deal.