[Ron Ramirez]

I think I remember what Ed L. did all those years ago to isolate those two trimmers -

Nylon hardware (screws, nuts, spacers) to hold those two trimmers in place, instead of the original steel hardware which not only holds the trimmers in place, but also grounds them.

Using nylon hardware is a quick and easy way to isolate the trimmers. Of course, wires must then be connected from the formerly grounded terminals of each trimmer to the respective terminals on each IF transformer.

Later today, if I am still feeling okay, I'll head to the nearby hardware store and (hopefully) get what I need to do this.