DavidD -- As an apprentice, I made my own set of parallels. That was one of the check-list items in those days. It was my introduction to using a surface grinder. Over the years that I worked on contract in various and widely spaced shops, many of that "set" sprouted feed and I broke down and bought a set from the widow of a colleague. That is supplemented by several matched pairs of custom parallels made for a specific purpose.
I also have two sets of adjustable parallels. The first set I had were made by me, but this disappeared in a move. I find it interesting when I see people working on jobs that, had they a second set of adjustable parallels, would be much simpler to set-up.