This picture may be self-explanatory. The spare ignition key under the heater box screw was an original factory accessory included for no extra charge with every new MGA from Abingdon (perhaps not for CKD cars). If you install one in your restored MGA it may be worth a point in concours show.

Photo courtesy of Tony Brown in Rougemont, North Carolina, USA.

Here's another one found on an unmolested original MGA 1600-MK-II "survivor" car. Original owner through 1978, the car had external repaint once more than 40 years ago (first owner), Second owner 1978-2021. New third owner in 2021. After digging the muck off of the spare key and and cleaning it up enough to see, it was left in the original location without removing the original screw. Photos compliments of the new owner John Pirretti