Don – I have downloaded and read a couple dozen PDF copies of “public domain” books from Google Books, some on carpentry and timberframing, and quite a number of 19th century treatises on bridge building, some written by patent holders...

But, I guess I'm just old fashioned enough that I'd rather have a number of them as hardcopies. Physical books are just easier to read, and it is somehow far easier to find those passages I'd like to revisit.

Astragal Press would be the folks to look to or partner up with to work to see a long out of print trade related book republished, it is one of their specialties -

http://www.astragalpress.com/book_index.htm

"We build too many walls and not enough bridges" - Isaac Newton

http://bridgewright.wordpress.com/