Have an old Beseler 23C. The old, "Universal Color" type. I can not get the thing to focus evenly across the easel. If I focus at the center of the image, the edges are out of focus. Mostly at the top, left and the bottom right. If I focus at the top, left, the center can be brought into focus but the bottom right will be out and vice versa. I can fiddle and fiddle with the focus but, eventually, I can get it to be close but not perfect. I have aligned the X-axis pretty well. If I fiddle with it, I can get the left and right sides to focus pretty darned close to the same point. I can't figure out if there is a Y-axis adjustment. I have tried putting several pieces of photographic paper between the negative holder and the bottom of the stage. If I put 6 or 8 slips of paper in there I can get the thing to focus pretty close to flat. But putting that much shim material in the trap every time I want to make a print will be a PITA in short order. Does my lens have some kind of astigmatism problem? Is there some way to ensure alignment of the lens on the lens board? Is there an adjustment of the front-to-back alignment that I'm not able to find? I have heard that this vintage of Beseler can be cranky in the focus department. Is this just something I'm going to have to live with?