I have found vinyl plotter blades on ebay, and I thought the shape looks like a cutting stylus, so I have bought a box to check if it could be used to cut records.
I cannot test it right now, because my lathe is not finished yet, but I have taken some pictures to compare it to a "true" cutting stylus I have (on a RCA 11850 cutting head).
Here are the photos (Plotter blade is on top, cutting stylus on the bottom):


These blades can be found on ebay by searching "CB09 Roland Blades", and are pretty cheap: about 3-4$ each.

Do you think they can be used to cut (or emboss) records? Has anyone ever tried this? The tip seems thin and sharp enough, but I have no experience to tell.
Thanks for your advices.

