Blue Book of Gun Values is one.
Blue Book of Gun Values
Try Blue Book of Gun Values
Standard Catalog of Firearms, The Blue Book of Gun Values, Guns Digest Guns and Prices, Gun Traders Guide. There's a nice history of this gun with a few pictures at the link to Four Ten UK
Gun Trader's Guide, Blue Book of Gun Values.
Check the on line auction sites, Blue Book of Gun Values, Shotgun News, Gun List, local gun stores, etc..
Blue Book of Gun Values
Blue Book of Gun Values
Blue Book of Gun Values
BLue book of gun values
Blue Book of Gun Values, auctions.
send couple of pictures
Gun catalogs