I was looking at the list of tools on vcalc.net and came across the one above. Is that a tool to cut the groove into the selector knob shafts?

It looks like the tool is marked as 101'029-1 but I haven't been able to find that in docs I know of.

It's a hand drill machine for holding a reamer or a drill.
I think it would not possible to cut the groove into the selector knob shafts by hand...

It's a Contina tool not available outside the factory - so there is no entry in the list (Service Handbuch - Special tools assortment).

Ah, ok. The picture is low resolution, but the piece chucked into it looked more like a selector knob shaft than a drill. There appears to be something on the post under the shaft which could have been cutting tool. I thought maybe the device was geared to extend and rotate the shaft appropriately to cut the groove. Kind of like a custom manual lathe just for the groove.