If you're in SEPA, I can advise a shop who will post them on GB. I used them last year and will again next week. Ridiculously easy.
Think about it. He's had a successful storefront for decades. His online presence is in the thousands. He accepts credit card from the buyers. All of that adds up to top dollar for your guns. He charges 15%. When you think about the time/effort to take pictures, list guns, etc., plus the extra 5-10% I believe with what a respected online dealer yields in sale price, it's an easy decision. He told me when he would list them and that I'd be paid 10 days after they received payment, or I could wait for a single check, which I did.
Forum members here are the likely a very good route and I would love to see them have a shot. Maybe start with a few and see how it goes, but it could be more work than you might be willing to endure.
Sorry you have to sell. Not crazy about it myself, but that's how it goes I guess.