Model Rocket News Idea Box - Shock Cord Attachment

From the Estes Model Rocket News, Vol. 3, #1, Feb/March, 1963.

Here's an early shock cord retention using an engine block. It's similar to using just a segment of body tube used in the Enerjet Mercury Little Joe I.
This tip came from 1963 when the the illustration showed a minimum diameter tube, a BT-20 or BT-30. I wouldn't try this in small tube models. Tube segment retention works best in BT-55 tubes and larger.

Model Rocket News idea Box - D.I.Y. Fin Marking Guides

From the Estes Model Rocket News, Vol. 4, #2, 1964.

I still use this method to make fin marking guides when the kit supplied guides don't fit correctly.

Model Rocket News Idea Box - Nose Cone Retention

From the Estes Model Rocket News, Vol. 4, #2, 1964.

Everyone has lost a nose cone (on top of a payload section) at ejection.
I've used this retention method for a few years. Sometimes a simple friction fit at the nose cone shoulder isn't enough.

Model Rocket News Idea Box - Piston Ejection

From the Estes Model Rocket News, Vol.3, #1, February/March, 1963

Here's an early piston ejection drawing making wadding or parachute protectors unnecessary.
A solid nose block is slid down and rests against the engine block. The nose block is attached to a shock cord and to the nose cone.
Note the engine block recessed down from the top of the body tube. it is glued in place and stops the travel of the piston. That upper engine block could block passage of the parachute.
The instructions say to securely friction fit the engine so it doesn't eject. Where is the ejection charge supposed to go or vent?
It's still a great idea and used in some MPR kits.