I have a fairly new (modern composite barrel) Schneider Componon 50mm enlarging lens that looks cloudy/foggy. This haze will not come off with cleaning, so it seems it's on internal elements. I see a retaining ring front and rear that holds elements in place. Has anyone ever taken one of these apart and successfully put it back together or is this better left to a repair service? Any recommends on affordable lens cleaning service? Would have to consider cost of cleaning versus replacing. It seems that darkroom gear is getting so inexpensive it may not make sense to clean this lens.