This one is not well documented, but apparently this Jemca Safety Mirror was at times a factory original issue part on the assembly line. From available information (public grapevine, forums and BBS), this mirror (with rubber safety surround and angled mounting stem) may have been supplied for French or German markets (by government mandate). Various headlight differences are well documented, but not so for this special mirror.

The car in the first photo (above) was originally purchased in Germany (or maybe France). Same mirror in the third photo (below). The second picture (above) is from a 1961 1600-MK-II , purchased new by a service man in France in 1961. So it is possible that both of these were French market cars. -- The marking on the underside of the stem base is JEMCA, which produced mirrors for many of the British cars in the early 60s and forward. So possibly MGAs sold in France had the safety JEMCA model installed.

It would appear those Jemca mirrors are still being made as repro units:
https://www.hipwellarden.co.uk/jemcaaccessories

Not a true "safety mirror", as they are designed to break off at the base so you do not get impaled on the protruding stem.

From a Jemca ad in "Motor" magazine from March 1964, John Morgan LTD was doing business as JEMCA/JEMCA Works out of Birmingham UK.

From Bill Tyson in Walpole, NH, USA: "The good folks from Hipwell Arden, distributor of the Jemca classic wing and dash mirrors for many British cars from the early 60’s, responded to my query. They couldn’t confirm if the mirror we’re discussing is the French “safety” mirror for the MGA; however, they did offer that "It’s certainly a 50's period Jemca mirror" and it’s "a correct dash mounted part as the stem was later used on the Austin Healeys and AC Cobras".

On 6/7/2023, Christopher Tunnicliffe in Wiltshire, UK wrote:
"My complete run of annual UK motor trade listings (“Trader Handbook – for the motor, motor cycle and cycle trades”) from 1945 to the 1970s suggests that the JEMCA brand only existed during the 1950s (ignoring the modern repro brand), with no mention before that and no mention beyond 1958. I’ve attached a couple of adverts from the 1951 and 1955 editions. These handbooks show that during the 1951-8 period, JEMCA was a proprietary name belonging to John Morgan & Co.Ltd. of 521/523 Lichfield Road, Birmingham 6 (Tel. East 2353)".