A Dave, said the top E saddle will be the one furthest forward, so if you set the top E saddle to around 80% (or say with 5mm of thread still showing), and measure from the top E nut slot (board side) to the top E saddle with double the nut to 12th fret distance, you should be fine for position and saddle adjustment. It's then just a question of getting the middle of the bridge on the neck centre line.