I believe the adjustment procedure will be Owners instruction Manual ( Handbook) as its not in the workshop manual I have in front of me.
I have the P4 adjustment which may be of assistance. For info. The Rover Sports Register have reprinted both the Parts book and Workshop manual for the P3 should you require them
Thank you roverp480 for your illustrated reply. if others on the forum get this sort of help from you we might have to look at paying you a retainer. I will have a good look at this now and get to work,sincere thanks again and best regards. Derrick.Smith. (deckell)