"A-720 is the Type Certificate number. The post is now off Craig's List, so maybe the auction is over. Rolls built O-200's under license, but I'm not aware of them building any smaller Continental 4-bangers. …"
"I'm assuming the "Rolls-Royce" probably means some license built version of an A-65 or C-85? I'm also thinking the "A-720" might be the serial number?
I can't quite make out the N number on that photo...
I have an old blue line print of drawing G1814 which I believe might be the drawing you are looking for. I am trying to figure out how to get a copy made and how much that will cost. Portions of the drawing are not very legible so it will…"
My name is Bill Skinner. I am the son of the Bill Skinner that was an Engineer for Ed Porterfield and who was the original designer for some of the Porterfield Aircraft. I was a pilot, briefly. I have worked in the Aviation industry for my entire career.