Not wanting to hi-jack the thread but just found this out, why didn't I think of it first duh.
Had a new alternator shipped out to me in france by paddocks (good price for a lucas 65amp)
Bummer I ordered the wrong hand the adjuster lug was on the top not bottom, hated the thought of the costs involved in sending it back so started trawling the net and found some advice from an alternator servicing firm.
Just undo the 3 body bolts and rotate the head to the next position,( nothing falls out or flies across the garage) and the jobs a good-un. Works too. Sigh of relief.