I am in the process of modifying the lower cowling on my VariEZe. I have the mold for a Boat-Tail cowling with a NACA scoop. I plan on keeping my P-51 in a reduced profile and then add the Boat-Tail to the bottom. Let me know if you can make it down to the Miami-Ft. Lauderdale area and I'll show you my project. It may be possible for you to comedown with your cowling and we can modify it down here.
Let me know