It's always interesting coming across old "custom" parts. I remember doing these when I wanted to put extended lug studs on my car for racing wheels but knew that I might occasionally put stock wheels back on. So, I found a bunch of stock lug nuts and ground the end caps off. As for the lug studs, I don't remember anything about them. They are about 61mm from flange to end or about 54mm from end of knurling to end.
$40 shipped for everything sounds good (16 studs and 18 lug nuts). I can't seem to find them for sale anywhere.