There is a nice book at the Headquarters branch of the St. Louis County library. It's called Mini: Thirty Years On. It's dated 1990. It's status today is "in library", and I'll check back in two days, and if it's not checked out, I'll be disappointed!

Headquarters branch is at 1640 S. Lindbergh Blvd.

 

I think I've gone through that book. I was researching the origin of bonnet stripes and I think I looked at all the Mini books in the local libraries.