Or just fly it with the gap. I have one I purposely designed that way, to put tape wraps on the ends of the sustainer motors - it's a cluster - acting as the thrust rings. It's not very noticeable.

Another idea, but lots of effort, is to drill/grind out the aft ring in the booster allowing it to slide all the way up. To make up for the loss of the aft ring, you could add an external hook to the booster. I've done that on several of my upscales. It lets me keep ~scale looking tube lengths while accommodating the longer (non-shorty) motors.

Here's one on a Quest T-30 upscale I did. (The fins on the booster somehow ended up with too much rake. I musta been a little careless on the belt sander...) Doug .



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