You're looking at the backside view of most dreadnaught ends (with variations in the number of ribs and panels). Some call them "reverse dreadnaughts" and I've heard "inverse dreadnaught" as well.
I don't see this as a reverse end at all. I think people are being confused by the two wider ribs, probably located at seams where pieces of the end are joined together. It might be a RECESSED end, in which the corrugations look pressed INTO the end, rather than proud of its surface, but I'm not sure if that's the case.
