A 'gill', btw, is a variable measure of liquid. It means quarter-pint in southern England, but a drinker wanting a half-pint in a northern pub would call for a gill ~ which is clearly what is meant in the 2nd line of Byker Hill ~ also seems to be the meaning in the cumulative Barley Mow song [Good Luck to the Barley Mow in the DT], which refers to 'the gill pot', & you would never get a quarter-pint pot in The Barley Mow [or any other pub], but you would certainly get a half-pint one.

~Michael~