Here's something that might be of interest. I have highlighted the actors I know.
Produced by Peter Saunders and The Mermaid Theatre Trust Ltd at the Duchess Theatre, London, on the 22nd July 1963 with the following cast of characters:FILM VERSION
Alfie ....................... JOHN NEVILLE Michael Caine
Siddie .................... GLENDA JACKSON
Millicent Martin
Gilda ...................... GEMMA JONES Julia Foster
Humphrey .............. DAVID BATTLEY Graham Stark
Woman Doctor ...... AUDINE LEITH (seen her, can't place her)Eleanor Bron
Harry Clamacraft ... GEORGE WARINGAlfie Bass
Joe ........................ JERRY VERNO Possibly Murray Melvin's character Nat
Lily Clamacraft ...... MARCIA ASHTONVivien Merchant
Carla .................... MAUREEN DAVISShirley Anne Field
Perce .................... PATRICK MOWER 
Bryan Marshall
Lacey .................... PATRICK CONNOR (seen him, can't place him)Tony Selby (as Lace)
Flo ........................ EDNA LANDORUnknown, either dropped or renamed
Annie .................... MARY HANEFEYJane Asher
Lofty ..................... ALAN TOWNSENDPossibly Sydney Tafler's character Frank
Ruby .................... MARGARET COURTENAYShelley Winters
Sharpey ............... DAVID BATTLEY (again)Or was he the Murray Melvin character?
Vy ........................ WENDY VARNALSUnknown, either dropped or renamed
Mr Smith .............. NORMAN WYNNE (seen him, can't place him)maybe Harry Locke's character, the Foreman
Directed by DONALD MCWHINNIE
Designed by DAVID MYERSCOUGH JONES
No-one reprised their role in the film you'll notice.
I'm sorry for not knowing the people I haven't highlighted, and for not remembering the ones in italics (who've been in some favourite shows). Is this because this production was before I was born or because they were mainly theatre actors? Infact, having just IMDB'd all these 'unknowns' I've discovered they've all appeared on TV, with Marcia Ashton very active indeed, appearing quite recently in EastEnders and Doctors.
It's always interesting looking at cast lists and this one, from the original stage production, which I've copied from my Samuel French book, has inspired me to start a thread about actors working together and perhaps never seeing each other again (something I take very badly if there's a good chemistry or partnership). Please tell me if you know any of the actors I don't.