Ok. I did it. I found a Federal 450 (4x5) enlarger head from source Aand am mating it to a base from source B. When the head arrived in the mail, the condenser lenses were chipped in several places from transit. In the collective wisdom of Apug, do I: 1. Pretend the condenser isn't damaged and print away? 2. Yank the condenser and fit a ground glass plate in its place? 3. Leave the condenser in and add a ground glass to it? Thanks in advance.