Thanks for the suggestions and repair examples; I think I'll try repairing the one with the fried end windings...

If we end up with these oddball fixes, we'll need to write an addenda to the alignment manuals...!:D

That would work Neil. I have seen that arrangement used in vertical centering (DuMont, I think).

It is not necessarily the same thing, but I have repaired wirewound rheostats (specifically, fuel-tank level senders from 1970s GMC Motorhomes) where the wirewound element connection was bad at the terminal end. I did this by scraping a loop/turn of the wirewound element near the end so it would accept solder, hooking a bit of copper wire through that turn, and soldering the wire from the scraped point to the terminal.

If your are clever, you can actually make a center tapped pot from one that is not center tapped. I did it for the verticle centering pot on my Midwest 16" set.

First find a wire wound pot of the correct wattage and resistance. Then grind off the rivets that secure the two outside terminal lugs to the resistance element. Remove the resistance element from the bakelite case.

Now the tricky part. Using a dremel tool you will need to make a slit in the bakelite case where the center tap terminal needs to be placed. Then place a piece of brass shim stock,about 3/16" wide through the slit and against the inside back wall of the bakelite case. Now re-install the resistance element so that the back side of the resistance element is wedged against the brass shim stock. Use small 4-40 screws and nuts to replace the rivets that were ground off inthe first step to re-secure the terminal lugs to the resistance element. Make sure that the back side of the resistance element is wedged tightly in a "force fit" against the brass shim stock. The brass shim stock now acts as a center tap to the wire wound resistance element.

This fix has been working flawlessly in the Midwest set for years. Give it a try and good luck!