A couple of years ago I've been to the Imperial War Museum in Duxford, which is a great place to visit, lots of planes and tanks. There are a few dioramas as well, one of them includes a T-34/85 an 88, and guess what, a building with a German guy with a Panzerfaust in his hands.
http://www.warmuseums.nl/gal/023gal.htm
And yes, there is no roof on the building, so it doesn't prove that the thing can be fired from a room. I just found it interesting. There was also a text describing, that the Germans used to take out the tanks from above, as the armor was weaker on the top.