Allin of croydon information needed

47 Ronin

Retro Newbie
Not sure where to post exactly but I’ve inherited a number of bikes/frames from my father.
One is an Allin with the frame number 999. I’m guessing that places it as a mid 50’s build.
My father cycled for Charlotteville CC and lived in the Woking Surrey area.
Any clearer dating gratefully received. Many thanks.