Perhaps not that rare, but I have not seen another.
Kiesling describes it as erstz, manufactured in 1915 in small numbers. I found it hiding in west Fort Worth. The blade is about the length of an S14.
It was a blob of rust when I got it. I seriously oiled it to stop the active rust. Of course I would like to have a nicer one, but how many of these are you going to run across?
