Reproduction cam nuts of the original style cam nuts have been made and sold for years. A lot of the repro nuts are not exactly the same size, i've used them. I've also used the cam nut tools. The inside parimeter of the AC&R fits the original nuts but not so well on the repro nuts. I've got the AC&R tool plus a couple of other repro nut tools in an attempt to try and fit the repro nuts.
With chisel marks filed, or an unmarked nut, the nut is very shallow where the tool fits. If the radiator is removed and you are lucky to have the right nut and tool, its not bad . with an impact tool. With an impact tool you can push directly against the tool to help keep it from slipping off the shallow nut. It can be very difficult keeping the tool from slipping off the nut when working from the side with a socket and pull handle, no matter how well it matches the nut. I used the vender tools and repro nuts on the gears that I replaced, through 97. Now that a new hex style cam nut is available for just over twelve dollars, Purdy Swoft won't be fighting the odball cam nuts again. I did put all of the odd ball nuts in a coffee can. I saved them with my little collection of purtys.