I agree that it could be a change in production. I also noticed that the boom supports and horizontal fin attach differently than the instructions show. The instructions show a "ring" that the fin bolts to on top, and underneath there's a flange that the two boom supports are bolted to, with a 20mm cap head bolt & a lock nut. The kit has each boom support bolted, on each side with a 8mm bolt into plastic. This is probably fine, as long as I don't over tighten the screws, which could easily strip the plastic. The only thing stopping me from drilling straight through & and using a longer bolt and lock-nut is that I would have to drill through the boom, and I don't want to do that.
Mike