I once tore a Wico condenser apart to see if I could figure out why so many of them fail or are intermittent. The answer quickly became obvious (see picture). On the left is the end view of the paper/foil roll. On the right is a view of the disk that makes contact with the foil, connecting the roll to the wire. See the marks where the contact was arcing and burning? There’s the answer.
I also attempted to dis-asssemble an OMC condenser and it was so well made that I couldn’t even get it apart without total destruction. Granted, I don’t remember what vintage the OMC condenser was.
