Hi Jim, I just saw your post a few days ago, and took some pictures of the shifter in my 1969 this morning. The back up and P/N switch are integrated into one part, and is avaliable from opgi.com and more than likely many parts suppliers. The switch fastens under the horseshoe on the passenger side (see pics). The red arrows point to the two screws that hold the switch in place.
Shifter PN mounting 2.jpg
Shifter PN mounting 3.jpg
HTH Eric
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