Nice question, and I see the problem now as it doesn't appear to be a well-covered field at all. Lots of grumbling about others being on a higher scale but very hard to find decent info outside of the anecdotal. Been an interesting hour reading about pay corps of the world though

. I thought George Forty's usually excellent British Army handbook might help but sadly not. Still, reasonably sure someone here will already have the definitive info.
Best I've seen yet is this sheet, for 1925+, somewhat marred by overenthusiastic copyright marking, which is presented as relevant to ww2, they seem high but presumably the figures are before deductions:
WW2_Pay_Rates.
& this for the Yanks:
GI Intelligence Dept - Pay.
One chaps memory of US Privates pay:
WORLD WAR 2 PAY.
A snippet from Peoples war:
BBC - WW2 People's War - Infantry rates of pay
A WAAF Clerk on 2s/2d a day:
WWII Stories
Cheers,
Adam.