Yesterday I paid for one of these, with additional 20cm and 10 cm wheels, a dust collector and a load of belts.
Bandschleifer Modell 2-S
This is probably the most money I've ever spent on anything for myself.
Now I just have to wait 6 to 8 weeks. And I can finally make knives more efficiently.
Currently I can forge a couple of knives, and I need several weeks to do the grinding and polishing.