It's a Featherweight size frame,,as opposed to their Regular size frame.
Ser# should start w/ 'FW'xxxx or FWE if it has ejectors.
Ejectors would be a plus as far as value.
Butt stock may be orig,,just the pad added. I think the forend is an aftermarket added edition.
Frame, lever and forend iron orig color case hardened. Trigger guard (and outside forend latch if it has ejectors) was blued.. Bbls rust blued.
Serial # will match on frame (action flat), bbls (bbl flat) forend (inside on forend iron if all three major pieces are orig to the gun. Some small parts are also #'d but you have to take it apart to see the #'s generally.
SxS's are kind of slow movers right now as compared to the frenzy buying a few years ago.
Mechanics good w/ good bores and extractors I'd think the 16 Field w/a pad would go for around $600+ considering the *** forend exchange and crack in it.
a lot has to do with where you try and sell it. Some places are shotgun crazy, others could care less,,especially about vintage guns.
LCS don't take kindly to dry firing. Pre-13 models even worse with their firing pin bushings in the breech face. The bushings have a habit of cracking from dry fire and half of the bushing rolling out the muzzle.
I think the bushing went away after about 1905 or 06 and you have just a plain flat face to the breech with firing pin holes looking at you.
If you have the bbls off the frame and fire one or both of the hammers,,you will be able to place the bbls back onto the frame but the forend won't go back on.
You have to recock the action before the forend will go back onto the gun. Don't try and force the forend back on.
Recock by rotating the cocking arms at the front of the frame each downward till it's hammer cocks on that side. A screwdriver leveraged betw it and the opposing arm is the easiest I find. Some use a very small cresent wrench to grab and rotate each.
There is a specialty tool that LCS made for their assembers and 'smiths to use. It's still around in repro form and many use it. It doubles as a mainspring compresser when taking the locks apart.
I was taught the screwdriver method at the Marlin factory.