markings on an Eddystone

I just picked up a Eddystone manuractured in July 1918. It's been refurbished at San Antonio. The barrel is HS. Very clean and bore is shiny with sharp lands and grooves. I took the whole thing apart and noticed on the inside of the buttplate there's one marking which is a "W" with a triangle above it with what looks like a "r" inside the triangle. There is also a "U" stamped to the opposite side of the screw hole. Also, the flap for the cleaning compartment contains the same "W"/triangle and the number 34. Is the buttplate from a Winchester ? I was surprised to see that the "W" on the rear sight indicates "White Sewing Machine". Any help would be appreciated. Thanks.
Marc

the W is Winchester.. not White sewing machine..
White sewing machine did supply M1 Carbine parts and other small arms parts, Hammers, safetys and bolts, dont think they made 1917 parts.
it is common for a mix of parts from other makers to be on rebuilt rifles.

I would go further than Chuck, its standard for the parts to be mixed up! (of course Chuck has seen a lot more than I have and maybe seen them all original but its seems rare)

E will be for Eddystone of course, R will be Remington and EN will be Eddystone or Remington. This sight gets you the right desctipon (some odd ones I think) as well as what and where the markings are

U.S. Rifle M1917 Markings

You should be able to ID the bands up front, sight and a lot of the internal parts by taking out of the stock. Some take tear down further to see the letters.

My three all have the E, R, or W for the barrel, bolt and receiver and then it is a mix after that with no common refrain. You would think W parts would be more rare, but it and Rs seem about the same and close to being as common as Es on an R or W gun, which should be a lot more. Go figure.

I will sort through mine and match up what crosses and lines them up closer but don't expect I will have them all E, R or W.