I’ve had the upper roller flame hardened and the lower rollers case hardened to 1mm depth by MTS in Clayton (Awesome people).
So far I’ve post machined the upper roller and one of the lowers. The outer diameter of the upper roller had warped so that it was slightly conical (about 0.2mm) and the bearing bores went out of round (to the tune of about 0.02mm). The bearing bores of all of the lower rollers seems to have closed up about 0.05-0.08mm.
I mounted the upper roller last night, pictures below. I also bought some 3mm teflon strips to line the gibs with from plastic centre in Cheltenham. I’m almost done with this damn thing…