I know I'm probably to only person in the re-enacting/historical costuming world who has done this but....I picked up Tudor Tailor once and put it back down...laughing. The reason is that the vast majority of the info in there is almost exactly the same as Patterns of Fashion. The few things that aren't are pure conjecture (including a few things I simply do not agree with). It's okay, you can all look at me in horror now. I know, I have spat upon one of the great costuming bibles...

The idea of mini slashes probably comes from the extant 1560's Florentine/Naples (?) gown. The sleeves on that are clearly mini slashes. However, in both the painting I posted and in the one of Elenora and her son (http://www.karen.htmlcreators.com/fleleonora.jpg) you can see panels held together by "something". In the case of the son portrait, it's buttons.

I did some searches at one in the morning and did find that firenzekat had done the same style gown. I'm pouring over her research right (http://katerina.purplefiles.net/garb/diaries/Eleanor-Medici%20mid%2016thC.htm) now.