Minimal Rocket (absolute barebones - v4)

My most bare bones rocket.
Straight fins, single wall construction for fastest print time and least material used.
It takes 6g complete with the nose cone which in today's prices for PLA add up to about 12 cents a rocket.
This should print in under an hour.

It features:
- a stop ring for the engine
- two hold tabs in the engine compartment under the stop ring to hold the engine at rest
- a "tow" bar in the nose cone and the top of the main stage to hold the nose cone and chute

Per