First, a bit of history to identify the four Mustunt versions. The Mustunt I was a .Fox 35 profile stunt trainer well capable of decent patters. The Mustunt II was much the same airplane using wing, tail, and moment arms of the Mustunt I. It differed only in having a full fuselage and cockpit. The Mustunt III was a Mustunt II with a tapered wing. It flew OK but was kind of ugly. When I added taper to the wing, I kept the flap hinge line at the same location as the Mustunt II. This made the Mustunt III nose unattractively short. The Mustunt IV was basically a paste up of the Mustunt II nose and tail and used the Mustunt III tapered wing modified to include dihedral and shock gear. It also used a OS 46 and removable tank. The goal, of course, was to have a very competitive airplane with a semi scale appearance.
I don't know if anybody ever made laser cut parts for the Mustunt II. Actually, the only duplicated parts were for the constant chord wing. Everything else except[t for the canopy and molded turtledeck could be copied from the plans. I do know that Kyle and possibly Walter Umland cut laser kits for the Mustunt IV. These may be available from Walter. Kyle is still around (I think). Plans for the Mustunts I, II, and III were available from Model Aviation February, 1953 and included in the Al's Models 4 disk..
In this post there is a photo of the original plan cut and posted from the Mustunt I, II, and III plans. The Mustunt IV has the nose from Mustunt II wing leading edge forward. The tail is from the Mustunt II from the flap hinge line aft. The Mustunt III's wing is unchanged except adding dihedral and the shock gear. The cowl and turtle deck are from Mustunt II original molds. Original canopies are Bearcat II from a Fort Worth airline mechanic named Sparky at sparky2@att.net. And, of course the power was upped to OS 46. It was a fun project to design an easy building but fully competitive airplane with sort of a semi scale appearance. It turned out well.
I mentioned before about the availability of the free, one click download, of Al's Models 4, available here on Stunthangar. For persons interested in Mustunts, there is a 298 page article on design, building, painting and flying the Mustunt IV, That Mustunt IV article in book 2, starts at page 88 and ends at page 386, a 298 page article on just one airplane.
https://www.youtube.com/playlist?list=PLkHUtj971Jgk_k-N5vVQX_as0dcVexiz4 This is a copy of the one click access to the Al's Models 4 Disk. It's called a hyperlink but there's no need to know that. Just click on the part beginning https: and ends with iz4.
This edited post contains most of the necessary information about Mustunts, especially the Mustunt IV. Sorry about the presentation but I'm trying to correct some posts where I was incorrectly complaining about my difficulty in posting and editing.