Green’s Dictionary of Slang

(UK Und.) a bunch; a large number.

1912		E. Pugh City Of The World 236: Cold stuff to handle at this time o’ the year. And I don’t what-you-might-say cotton to it, for that an’ a daffy o’ reasons. [Ibid.] 260: I could never mace – bamboozle – the fences wi’ one hand, while I kep’ a stew o’ mysteries, running to thousands and thousands – all to be split up small among a everlasting daffy o’ the boys – with the other.
1914		E. Pugh Cockney At Home 251: There was a daffy o’ people hollerin’ out jest now.