Hello, I'm new to this list and recently returned to photography a couple of months ago. I inherited an Opemus IIa enlarger which had sat in someone's basement for many years. It's a nice piece of equipment but I've been getting bright spots and wavy lines on my prints. I don't get the same effect when I put the negative in another enlarger. I've cleaned the negatives with film cleaner and lint-free cloth, and cleaned up the glass negative carrier holders. No good. Today I completely disassembled the unit from the light source down to the lens and cleaned up everything I could reach. It was fairly gritty inside. Now I'm still getting the problem, as you may be able to see from the picture excerpt attached. Any suggestions appreciated.