You can see from the first pic that another obstacle to making a narrower cowl is that the Oil fill neck leans outboard several inches. I thought about making some kind of "bump" in the cowl to make room for it, but I really wanted a sleeker cowl if I was going to go to all this effort. I contact Dan Weseman at SPA and he made me a custom valve cover with the filler neck almost completely flush with the valve cover while still allowing me to check the oil dipstick and add oil through the filler neck using the same cowl door. I want to retain the lare, "model T" doors as I really like the simple and broad access I had to the engine for preflight, maintenance, and repair. How much preflight can you really do shining a flashlight through a little oil fill door anyway??