Managed to get the diff stripped, found this when I took the nut and pinion shaft out.
needless to say the it looked like a unicorn had taken a dump in the bottom casing with the amount glitter and shiny bits in there!!!
thoroughly inspected the diff, crown and pinion gears and and surprisingly no damage what so ever!!!!! surprising because ball bearings are not known for their soft squidgy nature.
the play in the output shaft is due to worn cover plate bush.
gonna replace, input/output shaft bearings and seals as well as both cover bushes and seals and do the breather mod.
one question about the breather mod, did you just drill and tap it the whole way through the casing or just drill and tap the same depth as the airline fitting then open up the hole under it? on mine it only looks like a bout a 4/5mm hole in the internal side of the casing.