These cowl pins covers tool many hours to get a good fit. The internal cowl pin that I originally had were just too difficult to get in and out, even though they looked great. Every time I want to remove the cowl, I would have to get in the plane and pull out the pins from the cockpit. The problem is the pins are too tight and flimsy to work properly from the interior and it just became too inconvenient. So it was back to the drawing board and after some research I decided on these external cover plates. This is works much better, but oh what a job to make them. I would have probably been better off making them from fiberglass because shaping the aluminum back up plate and cover plate to match the cowl was a major frustration. I still need to do some body work around the covers to make them perfect. The backup plate is .040 aluminum sheet pounded with a rubber mallet into a wood form until it fit into the inside of the cowl. The cover plate is .050 aluminum and the screws are 6/32 Stainless 100 degree Torquex, into a #6 K1000 Platenut.
