[patrician56]

Work proceeding with the 90X restoration. Bakelite cap blocks re-stuffed as well as the metal cap box. Now I face a new issue with the tone control. 4 position metal housing switch – off and 3 additive levels of tone.
When I took the chassis out of the cabinet, I noticed a tarnished thin metal disc (approx. 5/16” in diameter) on the shelf below where the tone control was mounted. Examining the underside of the chassis, I saw where the disc used to be attached. It was one of the contacts on the tone control. The stem where the contact broke off looked granular, like the metal was stressed. The second contact fell off while I was removing the tone control. The metal at the break point also looked granular. The third one is still intact, for now.
Are contacts breaking off on the tone control a common occurrence? If so, any tried and true fixes?
I was thinking of filing the head of a small machine screw down to the thickness of the contact, drilling out the remains of the riveted stem and attaching the assembly with a lock washer and nut. Any other ideas?
Thanks very much.
Fran