Rusty.

I did one by having the lumps industrial hard chromed. They masked off all other parts, 3 hours in the tank and I had 4 thou all over to hone back in.
Worked a treat and took out all the side slop as well. Could work for the dolls head as well but would need to be plated as a seperate item masking off all but the bearing surfaces.
Neeed to hone in with a diamond stone though, too hard for arkensas.

If its doulbe underlug then the dolls head proberbly isent doing anything anyway.

Best wishes Mark