Well, I fitted the new A127 today. Smaller pulley as other have mentioned but seems fine. I had to shim the pulley and the pivot for the adjustment strap slightly so the new belt would be aligned with the other pulleys (I have the long nose water pump for ref). Belt was 930mm and is now 900mm in length, it could be 910 for a perfect fit I think.
The new alternator has studs instead of spade connectors, so I added ring terminals with heat shrink to make sure they stayed clean. I was alble to use the existing 10 gauge wire to the + terminal of the solenoid and the AL (ign light) wire that used to go to the 3AW unit and bridged the wire from the alternator to the ign light with a small tail with two insulated male spades, again heat shrieked to ensure they were sealed.
I’m glad to report that everything works and the charge continues after ten mins of driving. (Old alternator would charge fine for 10-15 mins then stop-off way to fail).