The only outside mirror in the 1959 356A Accessory catalog is the "Aero" mirror.
- Page 8: W12 Ausgabe Febr. 1959 . 5M . II 59 . KS
- Page 9: W12 Ausgabe Febr. 1959 . 5M . II 59 . KS
There are Accessories Brochures in Miller & Merritt,
Porsche Brochures & Sales Literature: A Source Book 1948-1965
The 356B Accessories Brochure (page 175) shows only "
9125 Außenspiegel (für Deutschland serienmäßig)" and the photo shows the Ponto Stabil mirror stamped "Talbot Berlin" with the mirror mounted on the driver's door.
The 356C Accessories Brochure (page 285) is the first to show the bullet-shaped Talbot mirror:
9131 Talbot-Spiegel Sportausführung, links, nicht montiert (Outside Rear View mirror Talbot, left,
not mounted)
9132 Talbot-Spiegel Sportausführung, rechts, nicht montiert (Outside Rear View mirror Talbot, right,
not mounted)
By the way, the same Talbot mirror options were available for early 911s for DM 22.50 / US$ 5.65.
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I was talking to someone recently who bought an early 911S from the original owner who'd picked it up at the factory and had them mount Talbots on the car. Apparently, the factory advised tall drivers to mount those mirrors on the fenders which is where they still are on that car.
I also know somebody with a very late 1959 356A Cabriolet that was originally his father's. It has a Ponto Stabil mirror on the door and early photos showing that mirror. That style mirror stamped "Talbot Berlin" was probably installed by the factory on the last 356As.
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I've always thought that--back in the day--many owners mounted mirrors out on their Porsche's fenders because that's where the first sports cars in the US (early British sports cars) had them and people thought that's how sports cars were supposed to look (cars in Britain still had "wing mirrors" in the mid-1970s). I still think that's the most likely cause but a few might well have been mounted there at the factory on special request.
My best guess is the mirror on the "early 356A" you're asking about was a "period" modification when the car was young but not at the date of manufacture/delivery.
If anybody knows when specific Talbot mirrors were introduced it's Aardvark International <
http://talbotco.com/> which now owns the rights to
Talbot Mirrors.