The Hindustan Ambassador was manufactured in Kolkata by Hindustan Motors from 1958. The early cars were almost identical to the U.K. made Series III Oxford although they continued to use the side-valve engine, gearbox and rear axle originating from the M.O. Oxford and Hindustan Landmaster.
Later on the 1500 'B' series engine was produced and fitted to the side-valve gearbox using an adapter bellhousing. The engine used a home-grown downdraught carburettor as, so I understand, S.U. would not permit their carbs to be built under license. A great many Ambassadors were fitted the 1500 diesel engine, very popular with millions of taxi drivers.
In the 1980's an 1817cc single overhead cam Isuzu engine and 5-speed gearbox was fitted along with a higher ratio axle and larger servo-assisted brakes. The excellent 2 litre Isuzu diesel engine was also used resulting in a very effective, economic drive. The body tooling received some attention to address the wear issues resulting in poor panel fit which improved things no end.
From about 2004, multi-point fuel injection became standard on the petrol models with disc front brakes, power steering, electric windows etc. Ambassadors had air conditioning for many years but no heater. A liquid petroleum Gas (LPG) model was also available. In the later years of production, the build quality was also much improved resulting in a quirky but useable car.
In the U.K. there have been attempts to import Ambassadors by various concerns: Fullbore Motors in Fulham brought in a fair number in the 1990's, also Merlin Garages (South Wales) brought more in around 2003. Quite a few have been imported privately but the effort required to get them road-legal and registered in the U.K. made this an expensive exercise.
Production finally ceased in May 2014 partly as a result of declining sales.
There appears to be a chance Peugeot, having bought the factory, may re-introduce an Ambassador of some sort at a later date. One to watch for, perhaps...