Semroc Sam 3 Build, Part 2, Parts Prep Before Building The Kit

The upper fin tip pieces felt weak to me in the kit supplied balsa. The burnt edges were lightly sanded clean.
Four new pieces were cut from basswood using the balsa piece as a template.

I used a single edge razor blade to cut out the new fin tips.
On the left is the initial cut.
On the right is the same angle after sanding and truing up the end.

The nose cone shoulder end could use some sanding.
On the right is the flat sanded end. The shoulder was re-rounded with some 400 grit rolled over a fingertip. The rounded shoulder makes for a better slip fit in the body tube end.

The center is marked before screwing in the screw eye. Mark a center dot with a pencil, roll the nose cone to check the center and mark again if needed.

TIP: The upper end of the tube is sanded flat with 220 grit on a block. This slightly roughens up the end of the tube.
Slide in the nose cone and turn it against the rough end of the tube. The rough edge will "sand" and form the shoulder lip, sharpening up the stepped edge.