Talbot Jr. mirrors are a sought after period accessory, in the correct time frame for MGA. They will be stamped "Talbot Co W. Berlin". These were installed on many sports cars at the dealer. Apparently the Cobra crowd will pay dear for a mirror of this vintage but concours judges need to be educated occasionally to note that they are a proper period option for MGs.

The smaller picture here is probably a legitimate period accessory, which only means it was manufactured during the right time frame to have been used on an MGA when the cars were in production. This is a fairly common general style for an aftermarket part, even many years later. If you see such a piece for sale, and were thinking big money, be aware that there were a number of cheap knockoffs sold in large quantity. Do not lay out the big money unless you can verify the brand name, preferably marked on the part itself. This one appears to be a "no-name" brand, meaning it has no visible brand marking, but may still be a legitimate period part if identifiable by unique shape of the mounting plinth and base.