Cartouche on my 1903 Rock Island??

Got a Rock Island 1903 that I believe has a born on date of 1917. It is about 8000 above the cutoff serial for the low number Rock Island rifles. It also has the swept back bolt handle. My first question is do you think it made it overseas to WWI? Secondly, the only stock markings I can find is on the left side of the rifle on the wrist kind of below the safety and it is a rather small rectangle with what looks like a 3 then maybe a G then maybe an M and then a letter or number unreadable and lastly a T or K. So maybe 3GM?K or T. Any idea of what that is? Thanks for any help. I’ve not had a 1903 before so learning curve here!!

Here are some pics hopefully!

Pics didn’t work. Hopefully this link to Imgur will! Any help would be great. I’m new to the 1903!!

Hope it works Imgur: The magic of the Internet

3GM-K is an often encountered marking that I don't believe has been definitively identified though there are several theories. I believe it is also seen on M1917 rifles.

URL works for my pics!