Yes, these stamps were in use, for postage and revenue use, for nearly 20 years. Hyderabad had a population in 1947 of 17 million, and as they were the basic letter and receipt rate, they came in for pretty heavy use. Lots of shades (none listed in the catalogues), and printings from who knows how many plates, which I hope some day to make sense of.
If you were looking for a cheap stamp to really get your teeth into, this would be a prime candidate.
A couple more examples of the shades:

