This really has nothing to do with manufacturing dies but I figured you guys would be more likely to have an answer. I have some stones that have recently gotten REALLY loaded up. The last place I worked had this nifty little "plate" that would basically dress your stones and produce a nice, new, flat surface. Does anyone know where I could find something like this or at least an alternative.

If they've really gotten loaded up with material then take a brush and some soapy water to them first. You have to really scrub them with stiff bristles to get the material out of the pores. Then take some carborundum powder and a lapping plate (you can make one if need be) and lap the stone against the powder. Scrub up again and you should have a nice new surface. The loading comes from not using any lubricant with the stone. Almost all stones have to be used with oil/kerosene/mineral spirits/soapy water/alcohol/or even water. It suspends the particles and keeps the pores open. The grade of carborundum depends upon the type of stone. Keep stones soaking (by grade) in an old coffee can filled with enough lubricant to cover the stones, that wasy they're always ready.

Here's a trick an old toolmaker laid on me years ago. He had two stones approximately the same size. When he wanted fresh stones he lubed them with oil and rubbed them together, using the stones to clean each other. Obviously it isn't the way to go if absolute flatness is required. If that's what you need the lapping plate is the way to go.