And here is one of two �Type I� iron crossguard examples that I had in the back of my mind, but could not find when the discussion was more active. At the moment I have no idea of where the other one is, which as I recall was a much better example.
In the images, it looks like rust has been fairly active inside the crossguard socket causing damage there. And at one end of the lower crossguard (opposite the motto side) it looks like it was in contact with some kind of moisture source. Which not only caused some surface rust, but bubbling underneath the plating. And what looks like thinning of the overall plating in that location.
1st image - From left to right: the skull link, the lower crossguard, and the motto side of the blade.
