The Association for Preservation Technology (APT) special project -- the Building Heritage Research Library -- is up and running and will continue to expand via the non-profit Internet Archive. Presently there are 100 documents available online, but the expectation is that over the course of time, this collection will expand to some 20,000 titles. The Canadian Centre for Architecture has partnered on the project, and will add some 4,000 of its documents to the public access web site.
For those interested in historic building trade catalogs, the Southeastern Architectural Archive retains a large collection that predominantly came directly from architects practicing in the New Orleans metropolitan area who received them in the course of doing business.
Image above: Cover design, J.G. Braun Company. Architectural Shapes in "Alcoa" Aluminum. Chicago, 1935. Available through the Building Heritage Research Library.