From UMich’s John Wilkin via LIBLICENSE:
„Klaus is essentially right about HathiTrust, and I believe that
roughly the same thing is true for Google. Per guidance from
Michigan’s General Counsel, HathiTrust uses a default value of 140
years for countries that use „life + 70“ for their term of copyright.
If the author’s death date is known (and significant resources are
going into determining death dates for some countries), the actual
death date + 70 is used. Now, or very soon, HathiTrust will be using
120 years for „life + 50″ countries; again, an actual death date
overrides this default value. All of this applies to users outside of
the US viewing works published outside of the United States, and the
date used (e.g., 1873) changes automatically at the turn of the year.“
This means that there is now a good chance for suggesting worldwide opening of works by authorts who were 70 years dead! My own experiences with opening of pre-1923 volumes for US-citizen are very promising.