I am taking apart a radio which I found (non-functional) at a scrap yard. Inside are a number of low value coupling caps etc. which appear to be paper in oil. They are labelled: "Industrial Cond. Corp., Chicago, Ill., U.S.A CIE 48703A. 600 Working Volts DC. 2x.1MFD. DO4" They're definitely not electrolytics as far as I can tell based on the circuit. No polarity is indicated. They are in rounded rectangular cubes with flanges so that they can be bolted to a surface. They mostly measure within 25% of their original or marked values. The values I've seen so far are generally from .01 to .1 µF. Any information is greatly desired. (I tried them in an old yamaha guitar and they definitely sound good)