Well, that's what it is!
The boys have done an excellent job with Marco's rear mudguard. Chopping it wasn't enough, they then molded (or moulded, depending on which side of the pond you're from) a rib all along the contour of the mudguard, to replicate the original detail, which got lost when they chopped it. Some sanding, priming and painting later, this looks like a factory piece and the difference it makes on the bike is really noticeable.
More on this soon: