Hi
I have found the make of carb - it's a non original (Japanese?) one - and I'm quite sold on the sales pitch!
"Nikki" is an English contraction/nick name of "The Nippon Carb. Co. Ltd", the oldest & biggest in Japan, established in 1932. Nikki scientists, knowing that one of the most important settings in any carburetter is the fuel level, decided to let you "see for yourself" and developed the famous Nikki float chamber window. Not only could you check the fuel level "at a glance", you could also check the fuel delivery, fuel pressure and possible fuel contamination, instantly. This is not possible with any other carburetter. The Nikki people then added their "secret weapon", an auxiliary butterfly in the secondary barrel, operated by the engine demand, effectively maintaining correct fuel/air ratio during all stages of operation. This is, in fact, a simple "variable venturi", which is why, to the bafflement of some so-called "carburetter specialists", we can fit our standard Nikki carburetter to nearly every car in the world, from 600cc Citroen to 2800cc Nissan Patrol. (jetted suitably, of course.) Our Nikki carburetters are all manual choke, they have no diaphragms, no solenoids, no vac. units, no auto choke, in fact, nothing to go wrong. Nothing is hidden from view, all moving parts can be clearly seen. This total lack of complication, coupled with the float chamber window, enables us to tell you and anyone else who will listen "THERE'S NO SUCH THING AS A FAULTY NIKKI......IT JUST DOESN'T EXIST" . An idea for Classic Car owners is to use a Nikki carburetter for everyday running and refit the original carburetter for showing or sale. This would preserve the condition of the original carburetter, often an item becoming increasingly scarce.