Note from the future: I had to add several more rings than you see here. For example, I had to add another hole in the top of the cabin, another three or four holes in the tail area, another on each landing gear leg, and that’s not to mention that I forgot to account for the elevator trim horns all together. If you are deciding where to put rings, I would suggest making a visit to a flying airplane with a similar configuration to yours to take detailed notes about where they need to be.
The elevator halves join behind fabric, and I think it will be much easier to get in there to install and inspect those bolts if I have an opening that’s larger than the usual ring. I made a larger rectangular ring for the right side, but used a standard round ring on the left. The round ring will use a spring cover, while the right ring will use nutplates and screws.
I also embedded a small piece of aluminum in the tail. I’ll rivet the dataplate to this plate after painting.
The interior will need inspection rings near the headset jacks.
Tapes, tapes, and more tapes!