Julian some interesting stuff that came up while searching the net. This is from the google books site. What is interesting is there's reference to these cars in US trade reports. Now Napiers were also built in the US. Was it that some of the Nizam's cars were shipped out of the US? I have also come across the coachbuilding name of Cunard. Any light on this? The following references are very interesting should we get our hands on them in libraries. Note the last ref which speaks of a lot of four cars being dispatched to the Nizam
The Beaulieu Encyclopedia of the Automobile - Page 1100
by G. N. Georgano -
Transportation - 2000 - 1792 pages
1910
Napier 40hp Purdah Wagon for the
Nizam of Hyderabad.
Daily Consular and Trade Reports
by United States Bureau of Manufactures, United States Bureau of Foreign and Domestic Commerce -
Consular reports - 1911
Page 45
A motor-car dealer of Madras has just imported a 6-cylinder 120- horsepower
Napier touring car for His Highness the
Nizam of Hyderabad.
Historical Motor Scrapbook - Page 103
by Floyd Clymer -
Automobiles, Foreign - 1955
1907 His Highness The
Nizam of Hyderabad. after testing many of the leading
British and Foreign motor
cars, selected the six- cylinder
Napier, as being most
Men and Machines: A History of D. Napier & Son, Engineers, Ltd., 1808-1958 - Page 91
by Charles Wilson, William Reader, William Joseph Reader -
Engineering - 1968 - 187 pages
... were united in owning
Napier cars. Across the Atlantic, J. Pier- pont Morgan
was a customer: in India, HEH the
Nizam and a whole pride of other princes.
... Automotive Industries - Page 710 Aeronautics - 1969
The
Napier firm has probably devoted more time and attention to this type of car than any other maker, and for 1907 no others than the six-cylinder
cars 
A History of Sports Cars - Page 44
by G. N. Georgano -
Sports cars - 1970 - 320 pages
... and '
Napier Racing
Cars, designed for 5 part in competition'.
... of whom the
Nizam of Hyderabad was the most The introduction of the Rolls-Royce Silver
... Motor Sport Automobiles - 1958
Page 439
On the same day a fine selection of old
Napier cars, numbering 14,
... Green's 1907 Sixty tourer which was supplied originally to the
Nizam of Hyderabad,
...
The Auto: The Motorist's Pictorial
edited by Stanley Spooner -
Automobiles - 1906
Page 1669
Above we are now able to give a photograph of four of the
Napier cars which have
been dispatched to the
Nizam. The two top
cars are respectively for HRH's
...