There are firms out there that will do an appraisal for your estate/insurance purposes. Depending on the value it might be worth the cost of doing so. One such firm charges in the neighborhood of $100 per gun for the first 3 guns, they drop the cost after 3. They prefer to have the gun(s) in hand but will work from e-mailed pictures if necessary or you can ship the gun to them. As I said your estimated value will be a factor in deciding to have a professional appraisal done. I know of one such firm in Northern Michigan (e-mail me if you would like the contact information) Good Luck!