FWIW, I have some NOS Shimano cones fitting the description of the CN-R036 in the Wheels Mfg. catalog. I got them for overhauling a couple of Maillard hubs. One hub worked out OK, but on the other one, the OD of the narrow end of the cone is too big for 3/16" BBs to work, and too small for 5/32" BBs. In either case, they change the OLD distance. On the hub where they worked, this was no problem, I only used the Shimano cone on one side, and used one less washer to compensate. On the other hub, the 5/32" BBs tracked more or less in the right place, but the cones moved so far inboard that I could not access the flats with a cone wrench to tighten the locknuts.
The Maillard cones I'm trying to replace have almost identical dimensions to the CN-R036, except the OD of the small end of the cone is only 10.5mm, vs 11.5mm on the Shimano cone. That 1mm killed the deal on the one hub.
Well, if the described Shimano cone will work for you, I'll be glad to send you a pair in the mail, gratis (other than passing on the gesture when you get a chance). And, if any of the cones that aren't working for you happen to fit the description of the Maillard cone I'm trying to replace, maybe we can do a swap.