Green’s Dictionary of Slang

1. (US) a moustache.

1928		M.C. Sharpe Chicago May: Her Story in Hamilton (1952) 132: Dot and dash – mustache.
1944		Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3.

2. money [= SE cash].

1962		R. Cook Crust on its Uppers 80: She’s none too well fixed for the dot-and-dash.
2002		D. Shaw ‘Dead Beard’ at www.asstr.org 🌐 One time lookers like Dionne are never happy unless they’re taking piles of dot and dash off some mug.