I had always assumed that the harmonium entered Indian culture via Western missionaries. But, according to this source:
Harmonium Indian Culture
the table-top version with hand bellows was created by one Dwarkanath Ghose of Calcutta in 1875.
Though I don't suppose he thought of the piano-style keyboard and method of sound production ALL by himself :-)
Fun fact: in 1995 I got a call to go down to Garsington Manor near Oxford where the movie 'Carrington' was being shot. They required someone to play a tune on harmonium for an outdoor party scene. The instrument that appeared on screen was a full console instrument, but what they gave me to record the track was a half-size 'ship's harmonium'. I wonder if this is the sort of instrument Dwarkanath Ghose saw?
The production company had wasted some time looking for professional harmonium players in the Musicians' Union directory, and finding only Indian classical musicians. Then they realised that a keyboard was a keyboard, and what they really needed was a hooligan who could busk something based on a WW1 era song. That fitted me just fine. Nice little gig.