Did you clean up the slip rings on the end of the alternator shaft Graham?, I did this earlier this week, using a red scotchbrite pad with a piece of cardboard to keep the debris from falling into the rectifier pack.
Looking at the brushes on your original AVR, they looked to be in decent order, compare to the ones I replaced on mine.....
The only other test you can carry out in situ, is to see if the stator windings are ok, you should have approximately .5 R across the two separate slip ring contacts, ie a virtual dead short circuit.
Also check fuse 14 in the passenger compartment fusebox, as this supplies the excitation voltage for the alternator
Brian
