Most sites I had links to are now gone. MS Windows Programming using C++ and MFC by Jon Pearce at the San José State University is the only one remaining.
See Windows++ Code Library about the book Windows++: Writing Reusable Windows Code in C++. The author contributed much to MFC and probably helped develop it but I can't find anything saying he helped develop it. The book however is unusual in that it shows how something like MFC could be written.