See John Orford & Jim Ward above. Both correct.

Wincott was a very popular music hall song writer and wrote many for the hugely popular singer, Harry Champion. Since it was recorded by Harry in 1911 we can presume Harry wrote it specifically for Harry and likely Harry'd been performing it for years.

I have the recording on a Champion CD. It it sung very much faster than we ever hear it today and is somewhat longer. It isn't hard to believe that some ancestor Copper (Bob's father?) actually heard Champion sing it and came away with what he remembered. Or else some other singer in the area did and so taught it to Copper, Folk Processing.

As above, it's originally "somebody said to M." in the words on Harry Champion; Cockney Bill of London Town; WindyRidge CD; 1911 & 2001. I like it.

AIR, it's "old stale beer" but changing it to the beer of the day or some brand the singer doesn't like seems reasonable.

I can't help but imagine that Wincott based it (loosely) on some local newspaper article of a pub fire (a tragedy anywhere, nearly as sad as Deportee).