There is the
Rule of shorter term, which should in general mean that the shorter term between the country of origin (where the work was first published, not the nationality of the author) and the country of distribution (where the downloader is) should apply. But not all countries follow this, and there are many exceptions. In particular, Switzerland (the country of origin of the site owner) does not apply the rule.
In short, the MR library follows life+70, exceptions, if needed, are dealt with on a case by case basis.