Here's a Morton M5 kit. A good friend of my Dad gave it to me when I was a kid(a while ago !) This was a project if you were a machinist. Detailed instructions and material were included. Spring wire to make valve springs. Some cool little parts. My Dad's buddy Wilbur ended up building a 5 cylinder radial from scratch later in his life. When he passed away, his wife donated it to the Smithsonian air and space museum. Last time we were there it was in a display cabinet.