I have an unidentified large wooden knob with a recessed center. Affixed to it is a brass plate with the GE logo in the center and around the edge what seems to read: "INOUT-OUT RESISTANCE". There is a serial number NP 14491 in small embossed letters. This comes from a mechanic's yard associated with the building of the All-American Canal (1934-1940). You can email me at [log in to unmask] to request a photo, if that will help. Thanks.