Guys, thank you all!
nonstoprc, that's just what I tried when I was on it a few weeks ago. Maybe the diameters of the dowels weren't that perfectly sized.
wagen017, Plettenberg didn't have any available, but quoted about 12 euros for the ring + 5 euros for regular shipping to Bulgaria. Maybe this would be a nice bet, because I bent and then straightened the original one, despite so far the motor seems to be running axially.
Aussie_Knife_Edge, I may try the heating or freezing method. I don't have a Dremel

Thanks!
Nickolay