It sounds like your shutter could use a good cleaning. Maybe check with S.K. Grimes Inc. http://www.skgrimes.com/ about cleaning your shutter, or take to a local camera repair shop and see if they will clean it.
As far as lenses go for your camera, you can use any number of vintage or modern lenses for it, from modern glass by Schneider, Rodenstock, Nikon, and Fuji, to classic lenses from Kodak, B&L, Cooke, etc... as long as the image circle is big enough. Check ebay for some good deals on vintage glass, they usually have a few lens boards listed for the 2D also. Hope that helps.