Thanks for all of the advice - I'll be careful.
Figured out how to remove the engine half of the clutch - the threaded stud is 'captive'. Once I undid the nut till it was flush with the end of the thread, a couple of gentle taps drove it in and the housing was freed.
My only real problem at present is rusted in Woodruff keys - lots of soaking and gentle tapping will release them I'm sure
I'll stop hogging DaveC's thread now.
Chris
