Several years ago, I noticed that the factory-fittted, over-under-under, twin-lens door mirrors of the 2003~13 Ford Transit Connect and related Tourneo minibus model (available in USA from 2009 onward), might have the potential to be adapted for use as cab-door mirrors for the 1968~79 VW Type 2.
https://en.wikipedia.org/wiki/Ford_Transit_Connect
The black, plastic mirror housing, is approximately 210 mm tall x 140 mm wide, so it's not much larger than the stock 1968~79 VW Type 2 mirror or Brazilian “bay-window” VW Type 2’s Transporter T3 style mirror.
http://www.thesamba.com/vw/forum/album_page.php?pic_id=327517
I envisage trimming off the stock Ford mirror mounting (flat, trapezoidal section which fastens to the door) and making an intermediate, moulded GRP or cast metal adapter, with sigle M16 x 1•5 mm bolt, to fix it to the profiled body section, just below the bottom of the cab window.
The top mirror lens, is the normal rear-view driving mirror, which is electrically adjustable, by means of the usual electric servo motors and four-way switch. I am told that on some or all of the vehicle-models, the mirror lenses are also electrically heated.
The bottom mirror lens, is a fixed, highly convex, blind-spot mirror, which enables one to see vehicles in the rear-quarter blind-spot, such as those associated with freeway on-ramps (i.e. motorway slip-roads), or simply overtaking on the freeway, one-way street or roundabout, of which there are numerous in Great Britain.
There appear to be a large number of Brazilian built, “bay-window” VW Type 2s and associated cab-door mirrors for sale on the following website:
http://lista.mercadolivre.com.br/
I have no knowledge of the Portuguese language, so I resorted to the Bing translator, to learn that “rear-view mirror” in English = “espelho retrovisor” in Portuguese. »
https://www.bing.com/translator/
After typing “VW Kombi espelho retrovisor” into the search facility, I found several links to rear-view mirrors, of which these are just a few for the late-model VW Type 2 cab-door mirrors, similar in style to those of the 1980~92 VW Transporter T3 (aka Type 25): »
http://lista.mercadolivre.com.br/vw-kombi-espelho-retrovisor#D[A-kombi-espelho-retrovisor]
Late-model Brazilian VW Type 2 door mirrorshttp://produto.mercadolivre.com.br/MLB-745518812-retrovisor-kombi-97-2014-karat-adaptavel-na-clipper-_JM
http://produto.mercadolivre.com.br/MLB-772672916-par-retrovisor-cromado-kombi-clipper-1998-2013-_JM
http://produto.mercadolivre.com.br/MLB-745630116-par-espelho-retrovisor-kombi-97-98-99-00-01-02-03-ate-2013-_JM
http://produto.mercadolivre.com.br/MLB-763650409-par-retrovisor-kombi-97-98-99-00-01-2013-_JM
Trawling further through the list of Brazilian VW Kombi, cab-door mirrors, there seem to be at least two distinct types of Vanagon style mirror; one with a single M16 x 1•5 mm fixing socket-screw and the other with a pair of side-by-side M16 x 1•5 mm fixing socket-screws. Those available from the Bus Depot in the USA, are reported to be of two-screws fixing type, which would seem to be the least appropriate.
Cab-door mirrors – two fixing screwshttp://produto.mercadolivre.com.br/MLB-733559756-retrovisor-kombi-cliper-pe-de-ferro-direito-97original-_JM
http://produto.mercadolivre.com.br/MLB-723500407-retrovisor-ext-kombi-cliper-fixo-original-97-par-_JM
http://produto.mercadolivre.com.br/MLB-820793720-retrovisor-kombi-1997-a-2013-original-ld-passageiro-_JM
http://produto.mercadolivre.com.br/MLB-804524152-retrovisor-kombi-97-2014-clipper-lado-esquerdo-original-_JM