Hi Bob,
Just come back from my old plans store [files] . Your model is most certain to be a version of Phil Krafts Kwik Fli 2. Plans were published April 1965 in the old US mag RCM , check out their plan No59.
There was and maybe still is, a smaller version in our own RCM&E from December 1968 a free plan, called Flea Fli at 38.75 ins 66% scale of the original size.
hope this is of some use, cheers, dejampea