Low Fuel Warning Light?? 58 Retractable

[Tom]

Greetings all, Just purchased and had delivered a 58 in very good shape. However, a rather large red light on the far left side of instrument facing is generally on all the time. Took it for an oil change before storage and noticed as I was coming down a hill, the red light flickered and went off and when the car went level, it came on again. No manuals and still looking for more info.

Never had a retractable and there's a number of small ticky-tack items with this vehicle. Any experienced folks have a second to chime in, I would appreciate it. Thanks!