I cobbled together a "semi-scale" Texaco cricket in the early Seventies...It did have oversize fins...and even on a B14-5 i remember it "coned" on the way up. I think it flew twice more thay day... but after a hard landing at the AARA home field the damage to the fiber fins (the adhesive backed card off of polaroid film) i think it went into the parts bin

RM