I've had some luck doing business with book finder services that
specialize in finding older books. You need to get to a local
bookstore or two and ask questions about such services. This
is what I did several years ago enabling me to finally obtain a copy
of "Architects' and Builders' Handbook" by Parker-Kidder.
I searched myself for several years -- literally -- it even took the book
finder nearly another year to find a copy but it did turn up and it was
a fair price considering the value of the knowledge in this particular
book which FYI documents and details every known mathemetical
construct known to the building design and construction process.
Good luck in your quest...