You could always see if the PA Auction Center fits your needs. They move about 400 guns at their monthly sales and advertise on multiple bidding platforms. I've bought and sold with them. You'd have to inquire on their current percentage. You can search their past auctions to see how the hammer...
You could always take them to PA Auction Center or one of the other Auction Houses with regular monthly gun sales. Yes, they get a commission. They also do all the handling, advertising, listing on multiple sites, etc.. IMO stuff generally brings what it's worth, sometimes more...
arrowdodger has helped lots of people solve pesky Marlin semi auto issues should the need arise:
https://www.youtube.com/@arrowdodgerluvsmarlins1758/videos
If they meet the requirements of no more than 7.5 lb rifle weight, no less than 3 lb trigger pull you can likely use them. I shot a number of the matches at Thurmont over the last few years, but did not see any there this year. There have been matches at Cresap lately but I have not been there...