You may notice one rather vital ingredient is missing: malt or grain of any kind. Not surprising, really, when brewers had their malt rationed. Hops, I suppose, were a bit different as there would have been some growing wild. Though you'd have no idea what variety or what the flavour was like. But that's war for you. You couldn't afford to be fussy.
If hops are available your district, why not try the following recipe for mild brown ale? Boil 5 ounces of hops for 40 to 50 minutes in eight gallons of water: put 4 lb brown sugar, more or less according to taste, in a large pan and strain the liquor over it. Add 2 ounces of yeast when the liquor is luke-warm, turn into a pan or tub to ferment for 4 days, then cask or bottle for use as wanted."
Western Times - Friday 01 August 1941, page 3.
Five ounces in 8 gallons is the equivalent of 1.4 lbs of hops per barrel. Actually a pretty reasonable amount for the day. in October 1941 Whitbread's XX Mild Ale only contained 0.76 lbs hops per barrel and their Pale Ale 1 lb*.
It wouldn't have been very alcoholic. I reckon 4 lbs of sugar across 8 gallons would give an SG of about 1021º. Quite a bit lower than commercial Mild, which was 1030-1032º in 1941. I'd have thrown in another couple of pounds of sugar myself to get something about 3% ABV. Assuming it was available. Because, as with everything else, there was a shortage of sugar.
Bottles wouldn't have been easy to come by. There was a shortage of glass and brewers usually wouldn't send pubs bottled beer unless they sent all the empties back
* Whitbread brewing records held at the London Metropolitan Archives document numbers LMA/4453/D/01/107