It will be part of a new model in the Combo Kit offered by Odd'l Rockets.
A launch lug has to pass through the shroud at the base of the model. The picture on the right shows a fit of the shroud around a 1/8" diameter launch lug. The sides of the lug slot are straight.
The top edges don't wrap around the top end of the lug. There are gaps.
Here's the new shape of the launch lug cut.
The teardrop shape ends up hugging the sides of the lug better.
The top corners end up wrapping underneath the lug.
A better fit, less to fill and more aerodynamic!
Well, about as aerodynamic as you can get with a high drag tail shroud!