Just done a search on here but cannot see anyone ever discussing the emergency door locking mechanism. I've had to remove mine as it is seized. Had to apply heat to get the inner handle off and need to drill out the screw on the outside one and probably a bit more heat as well. The collar on the main unit that the long chrome pole fits into is cracked/split so either a replacement or a complicated repair and re-chroming will be needed. The long pole is slightly curved but can probably be straightened sufficiently. The main gears where the handle is is seized but until the outer handle is removed I cannot get it off to take it apart.

Ideally a new lock mechanism would be fitted but I have no idea if these are available anywhere.

If anyone has any thoughts do please let me know

My bus number (if any): M1001, RML2276, T806

Had one of these seize a long time back. I just used a liberal amount of plus gas over a few days and gradually with the help of another person on the trolley steps we worked it loose.

Then removed the whole door/window and stripped it on the bench. It was mainly dried and caked grease.
Was a problem with the seal and spacers though which meant it leaked and also rattled. I made up some shims to allow a tighter fit.