Thread: Seeking plastic threaded self stud

My wife's grandmother left her this bookcase. It's screwed together so I don't think it's particularly old or valuable, but we like it. While wallpapering at the top of the ladder next to the bookcase, one of the shelves dumped it's contents onto the floor next to me, nearly dumping me off the ladder when I jumped in fright!

The culprit turned out to be one of the shelf studs. I haven't come across one of these before. It's 9mm in diameter across the wide bit, plastic, and threaded, and it sits in a recess in the bottom of the shelf. At the bottom of the photo is an idea the guy at Paddington Hardware and I came up with on a rainy afternoon - a brass bolt which I will decapitate and epoxy into the plastic tube and then cut to the right length.

Any ideas where I can get one? I'd be happy, even keen to replace all of them, which would be 8, plus a few spares just in case.