I don't know whether this is connected with the intended meaning, but in 'old' English/England, there used to be a style of hat called a 'mob-cap'. Because the story is about a tailor, and ribbons, I wonder whether the character might have been talking about 'ribbons for mob-caps'?
I don't know what a mob-cap looks like though
....... as far as I remember from context, it is a kind of hat worn by old ladies...