Yeah, and perhaps no one has done a correct figure before....
I've never seen a wargames figure with long gaiters. That said, that is no guarantee of anything.
However the Perrys are usually good at research and converting that research into accurate figures.
While some illustrations do show longer gaiters the photos from the period tend to show the short gaiters being worn by other ranks.
There are a couple of pictures that look like longer ones, but they could be either officers, irregulars or mounted infantry off the top of my head, they aren't clear.
Ian Knight's Osprey, British Forces in Zululand for example has illustrations that match these figures, so I would tend to believe these figures are correct.