Yes, I see your point but again - why does everyone feel the need to think the worst? Do you assume that everything in the classifieds section is stolen? No, I would say not. If the guns in question were nicked they would get shifted on locally not become the subject of a reasonable post on a specialist forum.
In reference to the OP, taking it at face value you have someone that has been left with a bunch of stuff by an ex. If he hasn't been bothered to get it back in two years it's safe to say that either he doesn't want it or he doesn't want the hassle of dealing with his ex to get it back. Either way it's fair to say in this instance that possession is 9 tenths of the law so all she needed was a pointer to say that she needs to make sure whoever buys the stuff has a defence and that's it. It doesn't need world war 3 yet again arguing the minutiae of the vcra.