Say jeff,
The value on an original trench Model 12 is considerably above 1000. Even if it has been re-blued (without heavy buffing). If the gun is original.
Your pictures lack the clarity that will be needed to sell it for value. From what I see, it either looks re-blued or is a gun that collectors dream of.
Haven't checked the market lately, but I would venture that if the gun is straight and has not been re-blued the value would be over 3 at the least, and probably higher.
Original trench guns do not come up for sale often enough to nail down a firmer price.
An auction might the way to go. There is a considerable number of Military collectors with money just waiting to be spent on a gun that would become their centerpiece. If the gun is original.
Have never seen a blued Arsenal re-work (only parkerized) and the heat shield is in the correct position and is also the correct type for that serial range.
That is in your favor, as there are a lot of parkerized (to cover a re-blue) fake trench guns out there.
I would practice photographing so that the images are sharper. Not meaning to offend, just to help. A prospective buyer will need them before shelling out that kind of money to a stranger.
If you are using a cell for the pictures. You should pick up or borrow a camera that has close shot capabilities. Outdoor natural light helps sometimes.
Get close,clear shots of all butt markings, the choke constriction/Winchester info on the left barrel, any heat shield markings, and a view of the muzzle (looking at the end of the barrel to see the fit of the heat shield on the guns muzzle).
A few of the gun in natural light would be good for better determining the blueing status.
Turn down offers that might come in on this one until you have a chance to be sure just how original the gun is.
My take, JT