Great looking airplane. MK no longer kits them, but Singapore hobbies has a great stock of kits and there's a good chance they may have one. The Skymaster was Kato's response to Yoshioka's Citation design one of the early inverted engine pattern designs. I think Bruno Geizandanner's Scorpion (designed around the OS .61VF) may have been one of the first along with Prettner's Magic.
Will B.