Every MGA roadster (not the Coupes) with original windscreen should have a small elliptical "Auster" tag at bottom center of the windscreen frame inside the car (secured with two drive rivets). Click for larger picture. Correct colors for this plate are, clear anodized aluminum background, red words, and a small pair of black "ears" near the rivets. (Ignore the pink background as that is a reflection from red paint on the body cowl). "Birmingham" at bottom of the tag refers to location of the factory making the windscreen assembly.

Auster is a name given by the Romans to a warm wind (very appropriate for the MGA windscreen). Auster Ltd was making aviation windscreens under the Auster Triplex trade name in 1914 (or earlier), about the time William Morris began making bicycles (1913).

A word of caution if you just purchased a new Auster plate. The current plate supplied by Moss Motors has the holes slightly misaligned from mounting holes in the windscreen frame. This can be fixed by elongating the holes in the plate slightly with a tiny rat tail file or a small grinding stone, or by "carefully" drilling the holes in the plate a little larger.