Rustam,
Van Ingen has long retired, though the old man apparently has a small coffee plantation out in the Nilgiris somewhere. He still has a collection of some of his old stuff that is well worth treating your eyes to. I can get you his details, though I imagine all you need to do is ask at the local gunshop.
Van Ingens were the top taxidermists in India, and even did trophies from Africa. Corbett sent almost all his tigers to Van Ingen.
M.
M