Yes: the Travancore authorities didn't much care what was for Government use. This is an example of SG 033, the 1926-30 3 Chuckram

They
did eventually get their act together with Official stamps. This cover

has SG 0100a and SG O105, and it shows that, once they gave up on the On S S overprints, the Travancore authorities did actually make an effort. Of course, in the mayhem of amalgamation with neighbouring Cochin State, integration with newly independent India, and the adoption of Indian currency, in the late 1940s, things got out of hand again

This cover of SG O2 is relatively free of faults, but all sorts of things leaked out to collectors at that time, like this block of SG O11cd

imperf between within the block. Curiously enough, these things are quite common mint ... but just try to find them properly used on cover!