Wish I saw this thread earlier, I redid all the brake parts on my 67 c50, converted it to hydroboost and dual master cylinder and still have all the part numbers.

I used a hole saw and cut notches in it for the rear axle nut. I found the real socket on ebay a few weeks later.

https://www.stovebolt.com/ubbthread...6602/re-axle-nut-socket.html#Post1386602

The socket is from Kent Moore tools #j-22343