Here's the Travancore stamp in question: it's just a Service stamp, but I recall not being able to find a 1 1/2 ch. in this colour.

That said, it doesn't mean it wasn't there. My brain was fairly addled after doing Cochin Achal, Travancore, and Jaipur yesterday. By the end, I probably wasn't capable of distinguishing a maharajah from an elephant.