Try posting on the CMPicon bolt action site.

Two guys have a huge amassed of background on rifles, more 1903 but definitely up to speed on 1917 (John Bear and Rick the Librarianicon)

You might see if you can get Mr. Ferris address and write to him with those pictures as well. He certainly wrote the definite book on these.

As you have found though, odd things pop up, it does look like its been refinished and or cleaned up, post the rest of the info and pictures.

Have you taken it down and do you have a list of parts stampings (W, R or E?)