Anyway, the antiques expert called the measure a "chota peg", which was the terminology of the Raj. I've looked this up and it means "small drink" in Hindi. The opposite is a "burra peg" or "big drink", an example of which might be a G&T.
The word "peg" is in my dictionary as a measure of spirits. Not sure if it derives from the above or if it's coincidence. Here's a quote from Lord Jim, by Joseph Conrad:
I've never been the worse for liquor in my life; the stuff ain't made yet that would make me drunk. I could drink fire against your whiskey peg for peg, b'gosh, and keep as cool as a cucumber.
Since the Scots seem to own the word "dram" for a shot of whiskey, and since they don't need any more advertising from us, I'm proposing we revive the word "peg". There is something Irish-sounding about it anyway and it comes across less Bertie Woosterish than "tot".
Right, I'm off for a peg of Black Bush. Yup, rolls off the tongue, it does.