I debated this in my mind, whether or not to do this now, but decided to go ahead. I don't see any reason why not to. So I got out my rivets, rivet gun and squeezer tonight and riveted the top channel to the roll bar.
Believe it or not, there's a bit more to this than meets the eye. Only a few of these rivets can be squeezed. Most of them need to be shot and bucked. I took great care to get them right, since these rivets are highly visible and I didn't want any dings or smileys showing here. I'm very pleased with how this turned out, and I'm glad I went ahead and got it done. The whole thing can still be taken out easily enough. I won't be installing it permanently in the plane for quite a while, most likely. But at this point, I can finally say, THE CABIN FRAME IS FINISHED!!
This was a lot of work. Much, much more than I anticipated. But it was probably one of the most rewarding sub-projects of the whole airplane so far. Very little was pre-punched or pre-fabricated for you. I added the cover underneath, and that took time and work. Those rough curved channel pieces sat on my shelf for a long time staring at me, and now they have been turned into a functional, beautiful finished part of this airplane. It feels real good to have this done.