I used the wrong word. Frosting is for decoration, flaking is the one. Small indents to hold oil, still have the long wavy line that leads off from the oil hole to spread oil around the surface. A small shaped chisel puts that in, smooth off the burrs at the sides after.i cant honestly give you an answer to that, i was watching someone on the tube, robrenz i think it might have been, suffice as to say there is even some science to the shape of that wavy track too, needs a little curve in it so as to let the oil move out and not act like a scraper and keep it there.
the ways would need something other than just a grind as you say, it might be crude but some time with a die grinder and a template Might get you back on track, they might still be there for if they have to grind past them the thing is too far gone nearly.
ill not say it lightly but id assume that i could do the frosting myself with the right tool?.