I'm thinking of making something similar for my Logan 210 lathe. I could make something that would bolt to the existing cross slide, but it seems like the best (certainly most rigid) approach would be to machine a single piece to completely replace the top slide i.e. with a dovetail cut into the bottom to fit the cross-slide ways, and about 3 inches high so my toolpost mounts on top. Maybe this is a dumb newbie question but - is there any reason not to make it that way, and any reason not to make it out of steel? The reason I ask is that I can get a suitable block of mild steel pretty cheap at the local used metal store, but cast iron not so much. Is steel sliding on the iron ways a bad idea, for wear or other reasons?