Richard, the scooping effect at 7 mph is not that great, however the possibility that the carriers were being slowed down by excessive drag was seen as justification for deleting the scoop.
Carriers were not the base design for Bluebird (a small plug for another great Kiwi)
Getting away from the heifer dust, (and FYI) the MkIIIw does have a slightly larger hole in the div plate, I assume, to compensate. I found this out when I used a MkI U.C. blanking board for a pattern, and cut a second one for my AOP MkIIIw, which then fell through the hole.
