I ended up with a few items from an estate. That included a nicely made multifunction valve of unknown application. It has both an aluminum threaded bushing and a white plastic one. Just for reference, the threads are not the same as a Nelson front rotor bushing. I don't have a rear-rotor Nelson to check.

Dave

Hello
This is from Italien TR  Engine Chipolla.

Klaus,

That certainly looks like it. The one you show has a pin (fuel nipple?) on the shutoff side. Mine does not have that. Perhaps one of the many, continuing changes on TR engines?

Thank you for helping identify this part!

Dave