The Conquistador.
That model is in the PAMPA publications "CLASSIC ERA CONSTRUCTION DRAWINGS" book compiled by Tom Morris. I highly suggest the PAMPA old time and Classic era stunt plan comiplations...much fun to peruse, and confirm the suspicion...you DID see that somewhere!
It is on pp.51. It is VERY handsome, elliptical, flapped wing, bubble canopy, rounded tail sufaces, sort of Spitfire style.
The designer was Thornton Hoffman, was published in the August 1958 Model Airplane News.
The reason I recall it, I have that August 1959 issue of MAN, but it would take a while to find it....(I just HATE all the time I have to spend rereading old model magazines, hot rod magazines, sports car magazines, etc...)
If you are seriously interested, I could xerox the article off and send it to you...I do not have a scanner...or, for THAT matter, a cell phone!...but I try to spend lots of $$$$ on models I never seem build each month. Priorities.
Lots of that going around me thinks.