Vintage patterns/modifications for breastfeeding?

Does anyone know what women of the 1950's and early 1960's did to facilitate breastfeeding while wearing fabulous dresses? Surely some women must have done it. Have you ever seen any patterns or old magazines that offer tips on modifying the dresses of the era for nursing access? Care to share with a mom-to-be?

I'll be home for maternity leave all summer (due May 15!), and I intend to spend my days wearing swishy retro sundresses, pushing the stroller, and having picnics in the park. I can't wear my Fluffy Cloud Dress every day, so I'm trying to find other vintage/retro patterns that I can modify for nursing. I think that free pattern from the Victoria & Albert Museum (pictured a few posts earlier) might work as a nursing dress by making the upper bodice piece an overlay that can be lifted up for nursing. Otherwise, I guess I'll be making dresses with front buttons and hiding my hungry baby under a blanket.

And tips or suggestions for patterns that might work?