In the Top Flite GS Corsair I redesigned the cowl mount so there are 4 longitudinal threaded studs in the firewall and the cowl ring is attached there. The cowl itself is attached to the cowl ring radially with small external screws in small hard wood blocks. This way the cowl flaps are part of the cowl ring independent of the cowl. You can remove them together or one at a time. I made the cowl flaps work on the ring too.
Turned out pretty slick and saved the cowl from the vibrations the single cylinder engine puts out. I had the cowl come loose in flight twice before I redesigned its mount. Operating Cowl flaps is another story...