Dan first of all apologies for double posting what Martin had already written. His replies were posted while I was still writing. Not only I am dyslexic so it takes a while to get a coherent sentence together, but I can't log into the forum on my Android pad so had to go to the phone to reply.
6A is spot on according to the EMER. I know you are looking for EMER POWER S522 as that Technical Handbook does cover the starter. But you also need EMER POWER P324/1 Technical Handbook Part 1 - Field Repairs & Part 2 Base Repairs that covers Starters No.1 Mks 1, 2 & 3.
Incidentally S522 covers all common features of the B Series, but to cover the B81 you also need S522/4