This spring steel band mounts on the inside face of the curved pieces at each end of the Cabinet Lid Frame or Dome Glass Frame on the Seeburg M100C.
It helps retain the dome glass into the frame.

I have several of these - all have been scraped clean but still have some surface rust and black residue from the rubber gasket material used to seal the dome.

This spring steel piece measures 21 and 15/16 inches long by 9/16 inches wide and has 8 oval holes punched in it.
(53.1 cm by 1.5 cm).