[TheForge] Upsetter Dog (Cam) faces

[Walter L. Mullett]

All of my tire upsetters have dogs (cams) with a toothed face to hold the 
stock.  Most of these are worn to the point where they do not hold well. 
These pieces are curved in one plane with the grooves running perpendicular 
(straight) across the face.  These grooves are a lot like a file cut because 
they engage in one direction.

What is the best way to restore the working quality of these short of a 
milling process?  The material is cast.

Thanks,
Walt