Here is the progress to date - the motor mount and coupler is bonded and the fins are dry fit. Looks like plenty of room for a bunch of 18mm mounts, right? Well, not so much with the Estes retainer slipped on. D'OH!
I could put the mount on the body or even section the body and have them partially exposed. If I wanted a cluster, the latter sounds like a good plan. But I don't, so I won't. Probably.
The fins won't be attached until maybe this weekend so I have time to ponder this build.
But, it will likely be a 4FNC, single 29mm. Probably.