just bought a 16" 1951 zenith porthole tv
 

I just Bought a 16"1951 zenith porthole tv I turned it on and the picture is not as clear as I think it should be. The guy I bought it from said it was fully resorted but that he had not turned it on for six years.The picture is also off center and there is a hum that i cant identify and I know nothing about electronics new or old anyone have any suggestions.

Any help would be greatly appreciated

Don