Sorry to be the bearer of sad tidings on those Indian stamps, Marc, but the problem is that they were printed and used in vast numbers. However, you
can find some interest in the postmarks, like on this cover sent between two of my favourite Indian States, Bhor and Dhar:

If you were wondering where the stamps went, well, they didn't go anywhere. The sender forgot to put them on in the first place. Here is the front of the cover, with the Postage Due marking:

The letter should have had a green Queen Victoria ½ Anna stamp, like yours.