From the diary of an ocean voyage (August, 1907). The diarist lives in Manhattan; she has just graduated from Swarthmore and is going to Berlin on a year's fellowship. She notes on the first day:

The first cabin passengers are also a mixed lot. It is not at all a fashionable crowd. Some even look eligible for the "chestnut wig" decoration.

Google is as puzzled as I am by this use of "chestnut wig." Does anyone get the meaning?

I never heard it before. It may be something so "inside" as a personal experience of hers.

There was a "mask and wig" club in the 1880s on Chestnut street, it was of course as tradition a all male production, with men playing the ladies roles

And some of the productions were perhaps pushing the social circles at the time.

Not saying that this is it, but it is a possible