Winchester 1897 Trench Gun-legit or a construct?

I found an 1897 Trench Gun in a small gun store, but I have reservations about it. Serial number is 734xxx, so it was made in 1920. It is solid frame and has stock without a comb. Barrel is marked CYL and it looks like it had a bead on it at some time, now removed or ground down. Large US letters without periods are on the left side of the receiver with a flaming bomb. Flaming bomb also is on the barrel near the receiver. There is a GHD cartouche and ordnance stamp on the left side of the butt stock. The heat shield has six rows of holes. The butt plate is plastic. I would appreciate any thoughts on this. Is it a "made up" Trench Gun? Many thanks!

Welcome to the forum, even though a description is provided, perhaps pics would help. There should be some along shortly that may be able to help without them...

Pics are here:
1897 Trench - Google Photos

I think we need a couple of the other guys to come look and say for sure. The "plastic" buttplate is called hard rubber.

Certainly looks Legit!

My concerns regarding this 1897 are that it looks like a gun that started out as a riot or trench gun in 1920, but has military markings of WWII on it ( large US on left side of receiver with flaming bomb, flaming bomb on the undated barrel). The GHD inspection mark would apply to a late WWII gun. Also, the crossed cannon ordnance marking looks unusual to me. But I realize there were variations.

That 97 has a lot of issues including, among other things, the martial markings. The stock cartouche is totally bogus.