So this project took almost two months, including three muslins. The waist and chest actually fit on the first cut. Cool! We used the rest to get the length and armholes/shoulders right. Mikey is really picky about the fit across the shoulders. He's really sensitive there, so we did a lot of adjustments to get as much range of motion and comfort as a sports coat would allow. I originally added 2 inches to the length of the first muslin, but that was actually too long for him. I think I ended up actually shortening the pattern by an inch. WHAT? Other than fitting adjustments, the only change to the pattern we made was omitting shoulder pads. Mikey didn't want them.