I trimmed the tabs on the fins, and then trimmed the fins themselves. The former I did with a hobby knife. The latter, due to the CA I’d put on the tip edges, I shaved off with a band saw. Might still need a bit of sanding but it’s close. And I think the new edges are more porous, so gluing them should not be a problem.
I fixed the bubble. Slit the paper along the bubble’s edge, forced CA underneath, pressed it flat.
On to the motor mount. No need for extra wide spacing between the rings any more, so I trimmed the tube down to its final length. Put in a thrust ring, because I will not be putting a 2-grain motor in this thing. A single cotton swab stick (as guide straw for the replaceable Kevlar shock cord leader) isn’t long enough to span the distance between the centering rings, so I spliced two together with some Kapton tape. Not that I worry about heat; if it gets hot enough for that to be an issue, the tubes will melt. But I have a lifetime supply of the stuff, might as well use it.
Then I glued the tube through the hole in the forward centering ring. The rear ring is still dry fit for now.Once that was dry I glued it into the body tube. These rings are a tight fit. Yellow glue would have been a tragic mistake. I used epoxy.