Estes Cosmic Interceptor Build, Part 7, Fitting The Fin Pieces

Here's the engine mount before and after painting gloss white.

Thin masking tape strips were set over the outside edges where the short tube (Part G) will be glued.

The yellow engine block spacing tube is set in the tube to keep out the paint overspray.

With Part S set into the notches (see picture below) check the joint alignment of the L, M, N, P parts.

It took very little sanding to get a better fit. 

Here's the Part S brace in place, no glue yet.

It's amazing how strong this assembly is.