I purchased an Aeropak Tailcone suitable for 76mm Motor Mount and 3.9″ Air-frame. The weight of all its parts together is 150 grams.
Here are some pictures of it.
I had to carefully sand down the motor mount external surface, approximately 1″ from the bottom to allow me to fit the threaded Aeropak mount component on. See pictures below.
I had to sand, then test, then sand multiple times, to ensure I didn’t over-do the sandpapering.
I have to clean the motor mount, remove the fibreglass dust to test joint and to ensure it is ready for gluing, later on.