Here's a newbie question, folks: I'm assessing what I have on hand to use in a darkroom - I had an elementary level one 30 years ago. I find stowed in my basement a "Vivitar 66" enlarger. Looking at the condensers, I find a moderate amount of dust, crap, and fungus on the inner surfaces. Problem is, the condenser assembly is a cheap sheet metal stamping obviously not intended for disassembly. Before I ruin this thing trying to get to the condenser inner surfaces, how important is it to clean these? What affect and how much will moderately dirty condenser surfaces have on prints?