Right do we want the Joan look rathe thant he betty?
I think the key is all sillouette to show off tthat figure.- you need suport undies, conical breasts (madonna was so past her time) and smooth unfussy lines in strong colours.
A cap sleeved sheath or straight dress is good like this from dull old next - below the knee though note and one like this for evening here and courts to go with it like these( no platform) but not in white obv
Joan often has a brooch too - very of the era, maybe given to her for services rendered...
A tiny clutch bag for her cigarettes and you are ready for a Manhattan.like this one