Bowhunter confessed:
"I put the large fins on backwards"
But I remember someone else did the same thing and posted pix here on TRF
Actually, it is easy to do because (I think) the kit directions are kind of poorly written.
So, cut them off and turn them around?
Don't tell anyone, just tell them you had the radical idea that perhaps reversing the fin orientation might improve the rocket's drag profile and result in better performance!!!
(I never 'make mistakes,' I just have 'creative ideas')