If Dad did have DPDT switches, I would not know and they are no longer on the layout. I suppose that is something else I need to consider. Is a DPDT necessary to install while I am connecting the PSX-AR?If this is already built, then there must already be electrical isolation in the tracks, otherwise it would not operate because of track polarity mismatch. Your second image shows gap locations, but it’s unclear if those are actual or proposed. Your father must have had DPDT switch(s) hooked up to manually reverse certain sections when it was DC. I would expect to put auto reversers in the same spots.