the threading is french..OK Thanks – and wow that is an impressive looking tool. And certainly wouldn't make sense for one time use.

It's becoming a bit tricky, I was all bent on doing this myself, to have the satisfaction of putting together this inner piece of the bike.
Already bought new bearings, anti-seize, and the correct stronglight crank puller (a cheapo one under 10€)

But I can see that it looks like not a good idea to mangle the flats more - so I either need to take it to a shop or find someone on the german bike forum board that might have the proper size fixed cup wrench at the very least. Looks like maybe the Stein fixed cup tool or copy could be found for fairly cheap...