I was lucky to find a local machine shop willing to make those, now they know me cos I'm 'that one that makes funny stuff with 'puters'
and no problem with orders. Although, my new barbs are not finished, so I worked a bit with those old ones. Here's the result, and a 'device' that helped me a lot, one ordinary 10 mm bolt to fit inside the barb, piece of rubber to keep the barb in place and not spinning, and a plastic cup to press the barb. Put it together and put it in drill press, little water and sanding paper and voila....shiny and smooth
They were a little bit too long, so I took a hacksaw while the barb is in the drill press and 'lathed' it to desired length
. Pretty easy and no hassle.