The stereotype reversal is a different universe (confusing i know) the one you are refering to is this one in it everything is reversed not just stereotypes.
Put simply it's the same as our world except that the role of women is played by men and vice versa. So anything that's happened in our world has happened in this world only with the gender roles reversed. So if you wish to do a story from a particular time period go ahead.
In terms of biology, I hadn't really thought about that. I guess I want men and women to genrally stay the same physically (ie men taller than women) but their clothing and behaviour to stay the same. So while men won't have breasts and women won't have penis, I guess the small characteristics could be implied for example men have big butts and this could be done through hormones.
Hope that helps, I look forward to your contribution
