When Numrich had these I bought some for $4.00 each. Nicely made and blued. I have also made a few, not to hard to do, take a piece of stock 3/8" diameter and turn the front down to the size for a 4-40 thread, then turn the body down to the size of the washer like head. I then part it off and place it in a bushing that had a hole tapped for 4-40 threads, thread in flush and turn head down. Place in a jig, I use Brownell's center head for slots and put slot in. Lightly file and burrs and then dip in Oxpho Blue.
The shiny screw I turned the head too small as to what it should be as shown on the others.
