I just managed to clean up the full flat grind and bowie clip point on my old Ontario SP-5 beater (vintage 1995). I am getting better at using the platen, but I still do smoother grinds without it. The edge leading grinding method on the convex edge (even with flat grinds I prefer a convex edge) is working out well on the new Delta. I stripped and sharpened the flat ground Ontario BQM combat kukri, too. The flat part of the belly on the SP5 has always been there. Ontario sometimes did some sloppy grinds.