I had a similar problem while doing the german translations one time, with ``"Last received block was generated %1 ago.``, in combination with the plural of ``%n day(s)``, which was solveable via chosing a similar meaning but not doing an exact translation. I can't really tell if this will work here, but I vote number 3.

Also it looks like we have 2 complete sentences and only the ``to`` is a little special.