We sort of discussed that in July, I think ...
here you go.
My best guess (which came out of that discussion) on PDF sizing was 3.54” X 4.85” with a .03” margin or 89.9mm X 123.2 mm with a .76 mm margin.
That ought to be a good place to
start experimenting, anyway.
Of course, we can't really
know until we
do have Readers to experiment on....