For a truly outstanding book on the history of the design and manufacture of the space suits, see "Spacesuit: Fashioning Apollo" by Nicholas de de Monchaux. It touches on interface as an aspect of the problem, and the industrial process of making and validating a proper space suit.
It turns out that making a space suit is a really hard problem -- and that "obvious" solutions, like hard jointed hard bodies, don't work. One of the keys to getting the suits was the sewing skills of the seamstresses, who sometimes had to stitch to tolerances smaller than the needles they worked with.
I don't remember the book as well as I like, I think another theme was the necessity of going outside NASA's manufacture and documentation protocols because the handmade manufacture process at the center of it all wouldn't fit. For all of NASA's emphasis on planning and documentation and process, the equipment actually on the astronauts was essentially an enormous craft project of hundreds of dedicated people.
Even with a project like constructing custom space suits, you can still have rigorous controls. For instance, they kept track of the count of sewing pins used to ensure none of them were left in the suit -- and all the pins used in assembly had colored heads, with a different color assigned to each seamstress.