Copyright law has been amended regarding "orphan" works, such that a lot are now free of copyright problems.
A kind of arcane area, but of interest to some, especially if those that can, start to be made available digitally. Some look very interesting indeed.
Here's the link to the article in today's Independent - hope it works, and is of interest.
http://www.independent.co.uk/arts-en...s-9824266.html