A new life - irving reborn after near fatal accident

[mekanik]

If it's possible to access directly beneath or above the rotating centre of the door hinge, either from the top or under the floorboards you could install an extension shaft to the top/bottom of the door that is in alignment with the hinge axis with a geared wheel, and drive this with a worm(and suitable motor) the motor housing could be actuated to swing the worm out of engagement for manual operation.
Not had a windscreen wiper motor to bits in a lot years but if memory recalls they might have some usefull bits, if it would produce the required torque.
Regards
Mike