This is a list of equipment that was used by each of the factions that was either removed, never added to the game, purchased in adequate enough quantities or lent leased. That would help fill gaps in with the Tech Trees. This also includes weapons trialed before the end of the war and pressed into the hands of soldiers before mass production.
USA/UK
Rifles:
Lee Medford rifle, BR II:
- 5 round bolt action.
Enfield No. 5 “Jungle Carbine”, BR III/IV:
- Has a bayonet lug and bayonet. Made by the UK. 10 round.
Enfield no.5 “jungle Carbine” Sniper, BR III/IV:
- Scoped variant of the Jungle carbine. Bayonet was removed.
SMGs:
Sterling SMG “Patchett Machine Carbine Mk 1” , BR IV:
- Made by the UK and Trialed in 1944. Used in more limited amounts during Battle of arnhem by airborne forces.
- Has a higher muzzle velocity ( 390 m/s) than the trash Thompsons. Accepts 32 and 50 round sten/ lanchester magazines or 34 round sterling magazines. 550 ROF.
45 - Remington Thompson 1923, BR V:
- Higher muzzle velocity than the standard Thompson (440 m/s). Made in more limited numbers.
LMGs:
BAR 1918 (40 Round), BR IV:
- Mainly used with AA emplacements, and rare cases of MG emplacements.
Anti tank:
M9A1, BR IV:
- largely the same as the M9, on both halves of the weapon you can see the variant.
- This can finally be a higher tier anti-tank for America, giving 140 - 180 mm Armor pen.
Italy/Germany
Rifles:
Gewehr 98/40, BR I:
- Originally a Hungarian service rifle, Re Chambered for German ammunition. 5 round bolt action.
LMGs:
VMG 1927/MV 31, BR III:
- 50 round magazine, Good option besides the MG-34 seeing it is this the only tier III.
Mg-81, BR V:
- Belt fed, finally Germany can go above 75 round magazines.
Anti Tank:
Solothurn S-18/100, BR II/III:
- Already in the games files The work’s already done for it. 10 round magazine. 45mm armor pen at 90°.
USSR
Rifles:
Rukavishnikov self-loading sniper rifle, BRII:
- Above picture with scope mount, presumably for the PE x 3.4 scope. 5 round semi auto.
SMGs:
Korovin 1934, BR I:
- Crudely built 25 round SMG, made by the same maker of the Korovin pistol.
Thompson 1928, BR III:
- 20 round stick mag version of the Thompson. Lend leased by the USA.
LMG:
Bren Gun MK I, BR II:
- Supplied by the UK through lend lease.
This would make a good alternative to the Madson MG.
Lewis Gun, BR III:
- Pictured above This looks to be Stalingrad. Yet another lend lease weapon from the UK.
Anti tank:
PTR-82, BR IV:
- 82 mm launcher first developed in 1943. Trialed at NIPSVO.
Japan/puppets
Rifles:
Vz. 24, BR I:
- purchased in mass from Germany because the aging type 38 was proving ineffective.
Type 44 carbine, BR I:
Type 5, BR IV:
- A later modification of the type 4 made in small amounts before the end of the war.
Murata shotgun, BR I:
- Single fire bolt action shotgun.
Type 97 81mm mortar, Tier IV:
- Japan badly needs a higher tier mortar.
These are not the only things that can be put on this list, but as this is taking hours to compile and put together looking at the research I will let some point come out with a part 2 to this.