chessieboy,
a bow is usually measured by the space between both nocks, the nock-to-nock length, or ntn length. don't bother to measure the 'stretched-out' length.
and I'm just guessing, but I'm afraid your making the rocket-science fault. My first bow had to be 2" wide, or 52mm. when I measured it, after cleaning up the edges etc, I found there was only 50mm left. I was shocked! but these exact measurements don't say anything about performance, looks, or durability. feel how it's done, don't try to measure it
Nick