Hi Dan, I also found interesting/scary the differences in the radio and manual revisions. To end my worries of the unknown radio version (last owner had it updated at Microair) I pinned it out with a meter and finally used pin-2. This helped me terminate the shield easier.
Regarding your power switch, replace it with new ones from Craggy , A-C Spruce, etc. The one on my 24 literally sprang open at the back; Yikes!
If you have any generic I/P wiring questions Richard at Craggy is very nice and knowledgable, so is Rick at Erie aviation. I hope your recent fix works full time, I'm still struggling with the crappy antenna installation, sigh.......
~Bruce
Lak17AT