What do I have here?

[J.Fife]

Hello all,
I had just inherited this 12ga, and being that it is my first Parker I was wondering if anyone could give me a ball park value for it. I had taken it to a local gun store and they really couldn't give me a value on it but had offed me $600 in store credit for it. Now, I am not planing on selling it because it has been in the family for a bit, but I would like to know what something like this is worth and what it would sell for.

Along the top of the two barrels it reads "Parker Bros Makers. Meriden Conn. Damascus Steel". On the water table there are three dates; Apr 11 1876, Sep 3 1872, and Mar 16 1875. Also on the water table there is a number 1, and just under that is a 5 digit number, and below that is the letter G. The barrel has three letters stamped where it closes up against the water table (near the extractor) and they are A, C, D, and also a number 14

The gun has two hammers, and there is engraved pheasants on the side. The butt plate has a dog on it. There is very little and light surface rust in a few areas but the gun is in overall great condition.

From my research it was made in 1887 and is a grade 2 model G. Now with all this info I can't seem to put a monetary value on it, and was hoping some of you enthusiasts could assist.

Thank you in advance.