You could try FFordes of Inverness. I’ve used them for dozens of items. They operate commission sales charging 20% which sounds a lot, but they get better prices than ebay or Amazon as they add value by checking everything and selling with 6 month warranty. You also don’t have the work to do of posting the ads, answering questions and avoiding scammers. Other dealers all (I think) buy off you, to sell on with a higher profit margin. If you call them they’ll give you an estimated sale price over the phone.