External Hinge of "Brandt" Washing Machine

Due to prolong use for my Brandt washing machine, original hinge inside the cover was broken and temporary repaired by AA super glue. Finally, I attempt to create a pair of external hinge which was fixed outside the cover. The problem is how to identify the center of the hinge. Finally, I use rule of geometry for perpendicular line of the chords of a circle which passing through the center. Two chords were marked by a marker which swing along the cover and two perpendicular lines were marked t