The old gearbox/transmission is now out of the car.
I’ll be splitting the transfer box from the gearbox, to make it possible to lift by hand. Then at some point, I will dismantle the transfer box to see what has broken. Maybe it will be repairable.
There is now a large space in the centre of the car, waiting for the replacement transmission.
I took the clutch cover off and the friction plate has plenty of life left in it. The release bearing is OK too, after a bit of WD40 and cleaning.
Just for reference, the release bearing appears to be the same as fitted to the Peugeot 504, 505 1971-89. Part no. HD4599.