You don't want chamois, as it would probably cut through very fast.
Anyway, chamois absorbs moisture, so I think it would make your blades rust, almost immediately! What you want is something non-water absorbent (e.g., oil the leather), and fit loose enough for air to get in. And of course, you should first dry the blades as best you can, and probably oil them - once you are far enough off the ice not to block the entrance while you do it.
The reason I am hesitant about using the plastic faux leathers you can buy at fabric stores, is that I'm not sure how tough they are, plus they don't quite look real. But reasonably thick leather is harder to find - you may have to order it if you don't have the right kind of store local.
I'm not sure how to crease leather for a clean crease - if you search Google for "folding leather" you see a bunch of links, but I haven't tried actually folding it.
The Zandstra guard whose link I sent you looks pretty simple to make, but I guess most sewing machines would break if you sewed thick tough leather, so you may have to omit the stitches, and only glue on the left end piece, shaped to cover your toe pick. (Or use a sewing awl - I've never used one, but they look simple. Maybe you need a drill to make the holes?) You can substitute cord (leather cord, if you want to be classy) for the strap.