I have a Lefever 12 gauge demascuss double barrell shotgun that also has a .38-55 smokless centerfire barrell that can be inserted into the shotgun barrell. i have a box of the .38-55 shells 255 gr soft point manufactured by Union Metallic Cartridge co.The serial number of the gun is 15543 E.I assume E is the grade. The trigger Guard has 1872,85,86,87.It is fully engraved with a dog and a pheasant on the right side and two quail on th right side.When i first got this gin from my grandfather about 40 years ago I located a gun shop operated by the Lefever Family in Rome NY. The completely restored the stock and did all the case harden bluing. It is in presteen condition. The only thing that was not redone was the demascuss barrells. I am interested in finding out the history of this gun and the value of it. Can someone point me in the right direction to get an appriasal?