Here is a seat belt reminder warning light. It would be wired into the output from a timed delay relay harness to light up when either door is opened and go off when the delay relay kicks off - similar to the ignition key light. I’m not sure when they were first used - possibly in 1966 when the same style. Take warning light was first used. They were used up until 72 or 73 when the warning lights were added to the instrument cluster. $40 shipped as shown from 22657
