Open latch broken on Vulcan Dishlex Grange (no model number)?

My wife went to close the door on our old Culcan Dishlex Grange. When she shut the door she said heard a sound like something falling down either inside the dishwasher or inside the door.

When she tried the handle to open the door, it felt like ther is no spring in it. As such the door is closed tight nd we are unable to open it. She was able to run the load normally though.

Does anyone know how that we might be able to manually release the catch or remove the door?

A service manual would be good too if anyone has one floating around.

We are loath to call a service person as the dishwasher is old, but we need to resue the dishes inside it.

Cheers,

Dale