Pictures would help.
I took post #4 to mean that the good lens is the one with a bent filter ring.

It's a little strange to have a modern lens that is so bad that you can see its softness on the ground glass. Even a small error in spacing would likely be able to make an image that focuses adequately on-axis but goes bad quickly off-axis. Typically, for a plasmat design, you can at least make a image with the individual front or back cells - it likely won't be critically sharp wide open but should at least be focusable. You could try that with each individual cell to narrow things down further.