A Mark I Welrod Pistol, can used for stealth kills at close range. The weapon is incorrectly depicted with the front sight at the muzzle rather than halfway along the weapon, a configuration only found on a Mark II.
Colt M1911A1
The M1911A1 is the first handgun you unlock, it isn't suppressed but has a higher ROF than the Welrod.
Luger P08
Sniper Rifles
M1903A4 Springfield Sniper Rifle
Mosin Nagant
Found in 4th mission with a scope
Gewehr 43
Karabiner 98k
Pre-order bonus, unlocked from the start.
SVT-40
Pre-order bonus, unlocked from the start. Semi-auto with 10 round mag.
First found in the 4th mission with round drum. Has the biggest magazine and highest ROF of any SMG.
Machine Guns
MG42
MG42s are seen throughout the game as emplaced weapons.
Grenades
Model 24 Stielhandgranate
First grenade the player unlocks.
F-1 hand grenade
Found in 4th mission, more powerful but less throwing distance.
Type 97
The Japanese Type 97 grenade is used in game as a booby trap. The choice of the Type 97 is odd, as the entire game takes place in the European Theater, however it is possible the developers wanted to visually differentiate trip mines from the other grenades.
Others
Panzerfaust
Found in mission 7 and 9, the Panzerfaust is a German, single shot, anti-tank weapon. It cannot be unlocked, and fills up the secondary weapon slot when picked up.
Lee Enfield No.4 Mk 1
In some of the missions which feature Russians, Lee Enfield rifles can be seen propped up against crates in Russian camps. It is unusable, cannot be picked up or unlocked (it is also worth mentioning that the Lee Enfield was most likely intended to be part of the game, as sound files for it can be found in the game's directory).