Back around 1959/1960 my father and I built a Champion 136 from plans. Looking at the side view of your hull, I woudld say, yes it appears to be a Champion hull. We never finished ours...bought the Lloyd hydro (HI-Q) and have ran that since. Don't know whatever happened to the unfinished Champion hull, we sold it, as is...would be nice to find it however...like to find the plans also...they're around here somewhere.
Pappy