Gearbox now fully disassembled. Unfortunately quite a few items must be 'put aside' for posterity and new items fitted. This includes all the gears, all the dog rings, all three selector forks, the oil pump, all bearings (every single one), seals, pawls etc etc.
The good new is that Rick Hall (Hall and Hall) has some unused but original BRM stock including selector forks and some gear ratios and dog rings plus the oil pump.
As for the limited slip diff components such as the pawls and inner gear I will write to ZF in Germany and a few specialty suppliers to see if they can assist with spares. Garry Simkin knows where the bearings and seals may be sourced from.
Garry doing some warming, necessary prior to progressive removal of each bearing carrier and shaft.
The oil in the gearbox was more a slurry of ground up metal and oil. The dogs on the gears and dog rings were severely worn and pieces snapped off components, such as the broken selector fork above. This slurry of broken metal circulated through all components including bearings and also the oil pump, as illustrated below.
Oil pump no longer fit for purpose!
What to do with old severely worn gears, the bin, no! - Christmas presents.
Old style ZF pawl locker diff. Hopefully ZF may be able to assist as it has a ZF part number punched into the outer race.