There are clearly a number of variants of this alphabet and some are datable from the references in them. My father's version, which he probably learned in the 1930s or '40s, is as follows:

A for 'orses (hay for horses)
B for mutton (beef or mutton)
C for th' 'Ighlanders (Seaforth Highlanders)
D for ential (differential)
E for Adam (Eve or Adam)
F for vest (effervesce)
G for police (Chief of Police)
H for beauty (age (be)fore beauty)
I for Novello (Ivor Novello)
J for oranges (Jaffa oranges)
K for answers (Kay Francis - 1930s screen actress)
L for leather (hell for leather)
M for sis (emphasis)
N for dig (infra dig)
O for a pint (Oh for a pint!)
P for a penny (pee for a penny)
Q for a bus (queue for a bus)
R for a mo (half a mo)
S for me (as for me)
T for two (tea for two)
U for me (you for me)
V for la France (vive la France!)
W for a bob (double you for a bob)
X for breakfast (eggs for breakfast)
Y for 'usband (wife or husband)
Z for breezes (Zephyr breezes)