http://www.wmboothdraper.com/
This website....under the link for tapes and lace. It's the only inkling I could find in regards to "lace" on hats.
http://www.woodedhamlet.com/tapes_braids/w...sted_twill.html This too. Although it really doesn't have any references per say.
As a side note- grosgrain ribbon is relatively difficult to get smooth on the edge of something round...because it's polyester. Worsted wool stretches nicely to fit things like hat edging, which is likely why it might have been used.
Edited to add: I have never seen a grosgrain ribbon that was anything but polyester, that's not to say that someone out there hasn't made it out of a natural fiber....but if they have, I haven't seen it in looking at many different ribbon sources. :)