Fins - While glue was drying, I filled and sanded and filled and sanded to the fins. The surface is not the smoothest I've seen but is acceptable. I beveled the leading edge and left the tip and trailing edge square.
Misc - I decided to add lugs and rail buttons so I marked the lower tube accordingly and built the launch lug stand-offs. The figure in the instructions show the leading edges beveled, so I did that. This was not written in the instructions. I don't know what I'll use for lug standoffs. I might just used a longer screw and two buttons stacked on top of one another.
Lower Body Assembly - I pulled the shock cord back through the mount and dry fit the mount and fins. When the motor mount is perfectly flush with the body, the centering rings are positioned perfectly. The pre-cut slots are a skosh bigger, which doesn't hurt anything since the fins are snug between the lower two rings. This section went together easily.
That's probably all until