Follow-up
John was kind enough to send me the above Lionel coupler set to try. Thank you John
The problem is in the design itself as reflected on the front coupler as well (which is not bent).
There is a known problem (as the search function here indicates) with the pilot constantly coming loose. That is fixed by using Blue Loctite threadlocker on the screw threads of the single screw that holds it in place. When fully tightened, there is barely enough clearance for the lever to go down to release the coupler. It hits the pilot. I suppose one could grind down the release pin until it worked properly. Yet even in the correct position the coupler in both the front and rear are too high. If one lowered them the coupler wouldn't open at all. Design flaw.
I ended up straightening the bent coupler arm and replacing the knuckle (which was also bent), spring, and rivet. I reused the original release lever and it works about as good (or bad) as the front one.
There is another unthreaded hole a tiny bit more forward than the threaded hole for the pilot screw, perhaps that could be tapped and used, but I don't know how the pilot would look. It might allow more up and down movement of the release lever for the couplers.
If anyone has done a complete rework please let me know.
Thanks for all the advice and help.
John