I found this variable capacitor at the local electronics surplus store. I believe the plates are phosphor-bronze, because they just don't look like brass. They are coated with some sort of finish -- presumeably to keep tarnish from building up. Here is a picture of the capacitor laid apart. The black plate is the one of the original bakelite side panels. A mirror image of that black plate was on the other side of the capacitor.


Here is just the capacitor and the rotor pivoted, on one of the HDPE panels I made for it.


Here is a closeup of the wire strip which is soldered to the rotor


Here is a the variable capacitor re-assembled with the HDPE panels. I made them extra long so I could easily mount it above a base board to keep the Q as high as possible.


I would appreciate any information about this capacitor. There were no serial numbers or manufacturer stamps on the original.