Here's my two penn'orth: wallah and babu are both Indian (from India, not Native American!) words, althiugh I can never remember which language. Wallah is an agent suffix, as in char-wallah, punkah-wallah. Babu means clerk, I think (lots of those in the Indian Civil Service in the old days).

Penn'orth? Pennyworth; c.f. ha'porth, halfpennyworth.

There's plenty to chew on at this site.