The earlier brass M1903 Springfield (and 1917 Enfield) clips had end tabs. The steel clips from WWII that I have seen have end clips too. The broke off in use with some regularity. Now, there is third type of clip - steel also - that is pretty much like the clips for the M14 rifle in 7.62 x 51 caliber. The M14 clips (I don’t know the military designation and can’t take time to look it up right now) were of a better design and didn’t need any end clips to hold the shells in. I don’t know when they were introduced, but there were clips for the Springfield that were designed like the M14 clips, and had no end clips. They had two bumps on each side (stops for the charger guides on the rifles), as opposed to the single, central bump on the later M14 clip. Your middle clip, I believe, is one of those. I used to have some and I preferred them for match shooting with my 03A3 (dolled up a bit with new sights and trigger). I gave them all to fellow shooters when I stopped shooting position rifle.
The M1 rifle was the dominant U.S. Service rifle of WWII, but thousands of M1903 variants and M1917s were used as well. In Europe, by the time of the Italian campaigns and the D-Day landings after, the M1 was really in wide-spread issue, but even there, a lot of rear-echelon troops had the older bolt-action rifles, not to mention some combat troops and snipers.
In the Pacific, the Marines hit most of the earlier-invaded islands with the Springfield. They started the battle for Guadalcanal with the Springfield, but as it went on, and M1-equipped Army troops started arriving, the Marines starting getting M1s through various means, and were pretty much equipped with them by the end of the battle, although I am sure plenty of 03s were fired in the last days of battle on that Island, none-the-less.
There were even some o3s and l3A3s issued in Korea to rear-echelong, and the Springfield 03, 03A4, and M1Cs were issued to snipers, with the Springfield dominant with Marine snipers, I believe. Could be wrong.
The first completely non-corrosive year for U.S. Ammunition was 1953, with some lots non-corrosive in 1952. I forget if any of the 1952 lots were .30-06, but probably. The .30 M1 Carbine round was non-corrosive from the get-go. They never issued any corrosive carbine ammo due to the problem of cleaning behind the captive, short-stroke pistol in those weapons. They are staked in, and while pistol-nut wrenches used to be plentiful at gun show, they were not an item of issue to every soldier, and the soldier was not authorized to ever break the staking with a wrench. That was 2nd or 3rd Echelon maintenance only.
The clip on the right is simply a standard brass German-style Model 98 Mauser stripper, and the never had end clips nor did they need them.
aYour 7.62 x 54Rs appear to be in a proper charger for them. They may just be reloads, or remanufactured military ball made into sporting rounds. Can’t tell with seeing the headstamps. Better 7.62 x 54r answer a question about them anyway. I don’t collect them, and have never even shot a Mosin rifle. Only had a mint Polish carbine version for six months because it was pretty, and then someone wanted it worse than I did, so I sold it to them. Good rifles, but not in my interest.