John,
It's actually a Fleet Air Arm Martlet flown by Lt. Dennis Mayvore Jeran RN off HMS Formidable during Operation Torch. That's the good and bad thing about decal sheets, there are now two more Wildcats that I want to build, this is one of them. I normally wouldn't want to but the US insignia on a FAA bird is intriguing. I remember seeing your Challenger at the Garlits Museum in 2012. I thought I had a picture, but I think it's on one of my dead puters. If you get a chance, the Garlits Museum is worth the trip. Here's a link to my 2007 trip if you're interested.
https://public.fotki.com/lewbud/garlits-museum-ptii/
https://public.fotki.com/lewbud/garlits-museum/