It appears your Bisley has been buffed and refinished which lowers the value. It is not a desirable caliber such as .45 Colt or .44-40. It also appears that the front sight has been filed down. In today's market, it could bring $1500-$2500.. Your best bet is to check the completed auctions on Gunbroker and see what they have been selling for. If you paid the fee to become a supporting member you could place it in the classifieds here and see what interest you get. Otherwise, you can place it on Gunbroker, sell it at one of the major auction houses, or see what a local gunshop will offer you.