This is a Swedish E A Berg chisel. I haven’t found another one so it doesn’t appear that my grandfather had a set of these. I didn’t remember to take a “before” picture, but I will say that it was definitely not apparent that the ring on the shaft was brass when I started.
From some basic internet searching, these appear to have a good reputation, but I don’t know a thing about them.
I really need to make a mallet.