I love my old Sabatier carbon steeleys. To make my Forschners and 1976 Henckels perform equally, I thin them using the coarse carborundum on my Norton Tri-Hone and grind using a very shallow angle, 15 degress or less and I couldn't care less if it's either 10, 15 or 17.5 degrees. As long as it's a shallower angle than stock. That works well for me.
I finish up using Hall's Black Surgical followed by the Idahone and a cardboard box.