how to get parts for door hinge for old Belling Forum 500 cooker?

I have a Belling Forum 500 cooker. List No 500BR A305972. It is in superb order except that the left hand hinge of the main oven door has gone wrong so the door doesn't close properly. I have an exploded diagram of the hinge socket assembly but I have to get someone to dismantle the door before I know which components I need. Before I go to the expense of getting someone in to do this I need to know availability of the of the various component parts of this hinge assembly. They are not available through standard stockists. Please can you advise re availability.

It would also be useful to know if I can get a new door seal for the main oven door and a bulb for the internal light.