Hello, Condition is everthing with gun collectors and here are two examples of the value of your gun. I have seen prices as high as $4,000 but most in that price range at a story of a famous person or event associated with them. So if I was looking to have this gun insured I would insure it in the $2,500 to $3,000 range. As far as value it souns like you be at least as high as $1,500 and maybe as high as $2,500. Thank You Tom Pleaswe click accept.
http://www.gunsinternational.com/Parker-Brothers-T-Grade-12-Gauge.cfm?gun_id=100073178&CFID=3959782&CFTOKEN=f1c053b8a08c7f01-4F54F3C1-C83E-C742-81AC7B439B9DED61 and http://www.gunsamerica.com/961076439/Guns/Shotguns/Parker-Shotguns/Parker_Bros_12_GA_Hamme.htm