A model of a 10 kV, 0 - 300 pF vacuum variable capacitor that I have.
It's stamped with C.M.C-147-684, which may be a model number. No other markings apart from voltage rating. It was listed as a Jennings cap on eBay, I think.
This is not a 100% accurate representation, but I wanted something to test fit into a mount I'm designing. Some notes are available in the OpenSCAD source.
No, this is not a printable functioning capacitor. :|