Here's a snippet:
For the lazy:
July 1931 Liverpool started clear ale.
July 1931 Birkenhead started clear ale.
July 1931 Manchester started clear ale.
Sept 1931 Economy Budget. Duty increased by 31/- per barrel
Sept 1931 W & Co. [Whitbread & Co.] Bottled Beer prices increased by 1/- per doz. pints; 6d per doz. half pints; & 8d per crate, except LS & LOS which are not changed in price, but the gravity reduced from 1055º to 1047º
Sept 1931 Bass Bottled Beer increased by 1/4d per doz. pints; 8d per doz. half pints
Sept 1931 Guinness Bottled Beer increased by 1/4d per doz. pints; 8d per doz. half pints
Sept 1931 Cask Beer. X.A. started at 118/- per barrel. K.K. & Stout withdrawn. Replaced by X.X.X. & L.S.
This is what happened when there was a sudden rise in beer duty. In some cases, the prices went up, in others the gravity went down. Net result: less tax income for the government.
This was the end of the road for Whitbread's KK and Stout. Beers that had been around since the early 19th century.
I don't know what XA was. I haven't seen it in their brewing records. Weird.
The clear ale stuff is, I believe, when various bottlers went over to carbonated rather than naturally-conditioned bottled beer.