I'm in this same position. I've been kicking the idea around of selling some of the guns that I never even look at anymore. I think as I've gotten older, my taste and interests changed so I'm gravitating toward certain guns more than others.
I also look at some of these guns like I'm just the care taker and maybe I should give other people the opportunity to own these guns and appreciate them as I did when I first got them.
I don't really need the money, but then again, maybe I could do something else with the cash instead of having it just sit in cases. It's a tough call.