Switches or knobs that control various functions like torque converter lockup, fans, line lock, fuel pumps, exhaust cutouts, etc.
Pretty much anything that needs to turn on & off.
The styles of the switches themselves varied depending on its purpose & who made the switch panel.
Sometimes they were plain, other times they had lights in them indicating the item is “on.”
This part is still available (they pop up on ebay, &/or some vendors run across them once in awhile, check swap meets, etc), or just simply trace out your ashtray & make one yourself out of thin sheet metal or a thicker plastic.
Here’s some other items if you’re shopping for Buick merch:
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