A renewed search of my Digikey catalog has part number 381N505-ND. ($13.35). This is a Clarostat 1 Watt conductive plastic linear pot with identical mechanicals to the original, which was also a Clarostat part. I was nervous about the 350 Volt rating, but if my calculations are correct, there is about 326 Volts across that pot in circuit, so it should be fine. Comments welcome.
I am in need of a new "focus" pot for my Tektronix 475 scope, serial number B278849. The part Identifier is R1380. The Tek part number is 311-0075-00. Description is: Res., VAR, NONWIR:
5M Ohm 20% It is a small all metal round pot with a 1/4" bushing an an 1/8" shaft. The pot works electrically but is binding/stuck mechanically. It can be rotated, but it is very, very stiff. I'm afraid of breaking the fiberglass extension rod.
