Those inscribed are marked just as shown and would be appropriate for use/display with any U.S. rifle of WWI vintage. Indeed, these were used long after WWI, well into the 50's, tending to outlast the rifles in service. Originally, the brass fittings would've been "blackened" with a coat of paint, which wore off quickly in service.
Generic information on the M1907 and background:
The U.S. Sling, Rifle Model of 1907, featured two sturdy hooks ( called "frogs" in some parts of the world ), was comprised 10 or 12 ounce leather strapping, 1 1/4", in two belting components: the longer by regulation ran 46-48.5". The shorter, bearing the "D" ring, was typically 24" to 26.5". Length was adjustable, and they were rigged standard with the hook "flats" facing away from the butt stock. However, originally, there were various other uses and applications for the slings, and they were often rigged "upside-down" by users who wanted the sharp hook ends AWAY from their arms while shooting.
These were used on the last of the U.S. Krag rifles at the end of their duty, all '03 bolt action variants, the M1917 "Enfield" U.S. Rifle, the M1 Garand, even shotguns, and pretty much any rifle on military duty which could/would accept a 1 1/4" sling. Rumors to the contrary, if properly conditioned, they held up better to most climate and moisture conditions than the later web. They were slowly replaced by web slings primarily because the web units were much cheaper.
Until well into 1942, metal fittings were brass, originally "blackened" ( that finish wore off almost immediately), after 1942 almost entirely blackened steel. The blacking could be phosphate, blue, or various paints or lacquers. It was adjustable for use as a shooting brace/stabilizer with a "sling wrap", and because it was so sturdy to use in that incarnation, many additional nations utilized them. Slings were issue at the unit level, and during World War II, generally, slings were OLDER than the rifles upon which they were first mounted. Part of the reason for this was the huge post-World War I surplus in military inventories, and indeed, many 1917 and 1918 dated slings remained in military inventories LONG AFTER WORLD WAR II!!!
These are all "to regulation", with the correct riveting and stitching in the appropriate places, using the newer, easier to adjust hooks. Original hooks seem to have been almost all of the "continuously curved" style, not popular in civilian use because of difficulty of adjust them until holes are somewhat fatigued. The holes were generally elliptical, and numbers varied.
The version--NOT PART OF THIS AUCTION!!--for the Browning Automatic Rifle used a third hook, and was called the "Model of 1907, Modified", albeit in service usually called simply the "B.A.R. sling" or the "1918", neither of which is CORRECT, but which are more descriptive for ordinary folks. Some versions of the B.A.R. sling were longer in gross length, and the extant theory is that these were intended for the original "walking fire" concept, albeit no hard documentation exists to absolutely verify that.