Centuri Flutter-By Build, Part 3, Engine Mount

There is no mention of a relief notch on the inside of the adapter.
You should cut one or the engine mount tube will be distorted where it presses down over the engine hook.

TIP: Don't cut the notch over the seam. The ring will want to de-laminate if the seam ends are cut.

The centering ring will have to slip into the outer BT-50 tube.
Round off the edges with some 220 grit.

The green layer is thin and may start to peel up on the edges.
Brush on a coat of CA on the edges.
Lightly sand smooth with 400 grit.

Here's the finished engine mount.

TIP: I also cut the notch for the engine hook so the exposed motor tube seam wouldn't go underneath the hook.
Now I can fill and sand the seam without the hook in the way.