Chuck,
I suggest MT 1023 assembled body mount couplers. Get a supply of 00-90 aluminum screws to mount them and a drill and tap kit for this size screw.
Here are the numbers: Body mount couplers,00102009. Tap & drill set, 98800121. 00-90 screws, 00112020. You might also get a coupler height gage, 98800031.
Armed with these numbers check out on line, Walthers.com, internethobbies.com, internettrains.com, 4nscale,com, caboosehobbies.com or your favorite ebay store or LHS.
The picture you posted is a bit too dark to see the actual problem, but by cutting off the plastic coupler mounts, you should be able to install the new MT. This would be the easiest way to convert and maintain the necessary electrical pick-up.
B-)