My new-to-me 820s

[wws944]

I noticed that same detail! Do the labels in both of your C's show Beverley Hills?

Both show Beverly Hills on the schematic diagrams on the inside. The newer one also has an "Iconic" label with Beverly Hills address on the outside of one of the side panels. The cabinet in the link in post #8 has the exact same label. But the label is missing on my older cabinet.

My newer one also has an envelope glued to the side panel containing a diagram of how to remove the side panels and undo the nuts holding the front grille piece to the cabinet. Needed for narrow doorways... The older one appears to have had that same diagram glued to the rear (as the one in the link does), rather than in an envelope. But at some point in the past it disappeared too. I can see the glue residue from where it used to be.