Yes I thought Sumatran too given the facial ruff and extensive narrow stripes. Given the time frame it could also be one of the now-extinct neighboring island races, which would be very cool. I remember reading a guide book to the world's zoos written in (I think) the 1960's and the author casually mentions seeing a pair of Javan tigers at a zoo in Germany.
@Arizona Docent not sure if it's the same book or not, but Emily Hahn makes reference to a pair in her book, also very casually, and also in Germany...