Need help with painting?

Today I purchased a painting at an estate sale that was signed by Fritz Wagner on the bottom left, on the bottom right is a C with a circle around it, I think it is a copyright symbol, it is about 30"X36", it shows some older men in a library or something and on the bottom of the gold frame that is around it it says "Heineman's Old Style Lager, LaCrosse Wisconsin" and you can see a sign through the window that say's the same thing, can anyone give me any information on this painting?