Monday I received the parts from Best Electronics.
I pulled out the bad plug from Port One (the only good one), and replaced it.
Likewise Port Two.
After a few problems- too much solder causing an odd short circuit, and some extra wiring needed- it works now.
Port Three still has a bad plug, and Port Four just has a new one "snapped in" for spare storage- after all, even Atari figured that they weren't needed, or why the two-port version?
This is unusual for me because for the first time since I bought the thing at a townwide garage sale back in 1998 I can now play games like Robotron: 2084 "properly."
Now, to find Space Dungeon!