I'll offer some opinions on the A&N .410. First, .410's do have a higher value than their 12 bore counterparts. Yours is a very entry level gun with some major stock issues with the forend and around the locks. And unfortunately the Army and Navy brand doesn't add any value. A comparable grade American double like Crescent Arms seem to fetch in the $400 area. Being an English made gun, its quality is likely to be better, so I'd estimate $400-$700 depending on the stock issues, from what I can see in the pics.
