you can easily figure out the numbers you need by using proportions and images of the watches found on the web...
if you need the lug length of a 42mm PO, find a straight image of the PO from the front face view.. then measure on your computer the mm of the diameter.. put that over the 42mm you know is accurate.. then measure the length from lug end to lug end, and then solve for the denominator..
your equation will look like
(measured case diameter in mm)/42mm=(measured lug2lug distance in mm)/x
solve for x
doing this is great for a quick and easy way to comparing 2 watches. its not going to work if you need an accurate to the 0.1mm measurement.