Yeah, I made some..
They have an 8 bolt? flange and are exact replacement for Laverda.. they have a Knurled aluminum cap. I think they were for SFC or Jota..
The originals were steel, the bolt to tank part with 8 holes and threaded snout.. but I made them of aluminum, then hard anodized them.
I kept a couple for myself, looking for them right now as I need one for a project!
I have cut the aircraft style out of a wrecked sportbike tank, you can graft them in with a lot of work..