Torellian Invader (3" or 4" upscale)

From Danno's Rocket Wiki

This is a placeholder page for a future project, to scratch build a 3" or 4" diameter upscaled Torellian Invader.

With fiberglass tube fins, it would probably require significant nose weight and a high thrust motor.

A 3" upscale would be 5 feet tall; a 4" would be 6' 8" tall.

For this rocket, it would be cool to mount (for instance) 24mm black powder motors in the tube fins. (E12-0's? Dare I?) With a 54mm central motor, it wouldn't matter (stability wise) if some of them didn't light. Do tube fins have to be completely hollow to provide stability?