A fistcheneisen: a special chisel for installing a European leaf hinge

A friend of mine has a wonderful collection of odd hand tools collected over several decades. Recently he showed me a couple of fistcheneisen, which I will loosely translate to "hinge fitting chisels." These are meant to install the thin leaves of a European hinge into to the rails of doors and windows. The chisel and the hinges were new to me.

I don't have a picture of his chisels but here is one from the internet:



The two ranks of teeth on the back are meant to remove chips after the chisel is tapped into its thin mortise. The chisel and mortise in this case is less than 1/8th inch. 

My friend tried to describe how the chisel was used but since I had never seen the hinges I didn't understand what he was talking about. Recently he sent me a link to this video which made it all clear.

https://www.youtube.com/watch?v=3cQaLbYRjD4

Am I the only one who never knew of this? Do I need to get out more?

I looked around the internet a bit and I'm not sure these chisels are made anymore. Do any of you know?