I think you are over-complicating this a lot.
Case reeds are going to require much more fab than just making an intake for the Metra80.
You are stating that you "hate to lose the reeds" but honestly the Metra 80 is a GRUNTY cylinder that should have no problem moving just as it was designed. I would focus more on getting the motor built and fit to your frame, and less on how you can get reeds on the cylinder.