I seem to remember that some of the guns were very distinctive, do you have photos of them that you could produce if you find them up for sale. Even then you will probably need the police to attend as I can’t see them being handed back willingly, especially if the dealer paid for them him or herself. If violence erupts your just as likely to get arrested as the other party.
I wish you luck getting your stuff back, but don’t let it lead to violence, walk away if things get nasty.