Hi skytrain10.
Isn`t funny that both answers came from the Low Countries. We know our classics!
You made my day with your post. I got the same aircraft in my database twice and now I can finally make the combination.
It seems the aircraft started as the Thompson Special by John. A. Thompson and first flew in September 1977 as N51TD. It was built, I understand, purely for personal use and was indeed based on a modified Midget Mustang fuselage. Engine at the time was reported as 310hp t/s Lycoming TIO-540. Apparently Mr. d`Alessandris later modified it as racer (JT-SP for John Tompson Special?), got registration N71RH and engine was then reported as 417hp (modified) IO-540.
Externally N71RH differed from N51TD in having a prominent dorsal fairing ahead of the vertical tail.
I think Teusje and myself will now rest on our laurels (don`t know it that works in English) and suggest OPEN HOUSE