Southern English mixed drink

"When I've the taste for something, I'm a stubborn man. A huckle-buff or nothing."
"Can't make you a proper huckle-buff, sar, as I haven't barley-water"

- The Difference Engine

I first read The Difference Engine many winters ago, my introduction to the steampunk genre. I mostly enjoyed it, found it intriguing. But already I digress. There's a moment when in Iteration the Second - Derby Day, Edward Mallory tries to procure a drink he calls "huckle-buff". The barkeep apologises for having no barley water and Mallory moves on.

My quest to find out about this drink took me many places. It began with the 1811 Dictionary of the Vulgar Tongue (a great book to dip into), wherein I read that it was "beer, egg, and brandy, made hot". That's all very well, but where does the barley water come into it?

More internet digging showed that it was also known as "huckle-my-buff" and "huckle-my-butt". Huckled butts? Not what I sought, but I ploughed on. Yet another record shows it to be "Gin and Ale made hot". Drunk by the pint, this was clearly more ale than gin (and three pints was a lot), but what happened to the eggs?

Assumption Time

As fact has given me up, here's my take on it. References are made to hay by the same name, and huckle is a dialect word for a stook of corn (wheat), as well as the hip. Buff, then as now,can mean naked, for what it's worth. Is this, then a general term for a mixture of things? Hay at one time was the reason for the cultivation of a true meadow, a mix of grasses, flowers and herbs, so maybe the term also applied to a generic mix of spirits and beer.

There were, and are, many mixed drinks that go by the same name, black and tan being among them. My guess is that huckle-buff is just such a drink, and I imagine that an itinerant travelling the country around London would meet many variants.

The barley-water reference still gets me though. Possibly, as Mallory was a "Sussex man", this was a local variety of a Southern England mixed drink, one that required it as an ingredient. Maybe. Perhaps one day I will receive an email from William Gibson and he will set the matter straight. Then I will owe him a drink; just possibly, it will be a Huckle-Butt.

Tem42 says re Huckle-buff: I can't help but think that it must be some sort of alternate history pun, but I can't come up with anything other than the rather random "skin of {one's} ass".
The English Dialect Dictionary
The Experienced Farmer