Like all weapons in Wolf:ET, Panzerfaust is really close from today weapons, so it's easy to replace it with a more up to date weapon.
RPG-7 is using almost the same external grenade plugged into a tube as the Panzerfaust so, swapping it with the RPG-7 is just like changing the model's skin.
however, there is no reloading animation for the Panzerfaust, so the needed animation is just a statical model. When the grenade is fired and launched, the animation is just the progress of the missile handled automatically by the engine.
Considering the speed at which the rocket is progressing, it has been necessary to slow down the rocket a little to see how it behaves.
For the flamethrower, the animation is just a static pose, so, in this case too, a simple skin swap allows to replace the Wolf:ET flamethrower weapon and we can also reuse the original sounds as they are really close.