Truly unique, a one-off, solid silver presentation slide rule signed in script. Measuring 12 inches in length and folding out to 24? Dhunjeebhoy Rustomjee was the second son of Rustomjee Maneckjee (1766 - 1812), who was Master Builder at Mazagon Dock, Bombay c. He married the daughter of the docks owner (Rustomjee Cowasjee) and built the'Syren', the. Was owned by Rustomjee Cowasjee, born in Bombay in 1792 and came to Calcutta in 1812. Also known as Rustomjee Cowasjee Banaji, he was the first Indian to venture into partnership with the British. From the estate of the late James Kedd for Rs 2,51,000 and also the Sulkia Docks.