Danny,
Many thanks for that. I am now beginning to get the bigger picture. The book I'm reading is the story of Harjinder Singh who joined No 1 Squadron as a Sepoy (lower than any rank in the RAF) in 1934. This Squadron eventually became the first totally Indian squadron led by Sqn Ldr Jumbo Majumbar who eventually became the Chief of the IAF. In fact it is interesting that, in the post war years, almost all of the top VSOs of the IAF, including Harjinder, hailed from this Squadron. This was the main reason I failed to see the bigger picture. Harjinder's responsibilities did not really broaden until the war had ended and he headed up the IAF Maintenance Command based at Kanpur*.
I see that the VV squadrons were largely formed from a number of mostly volunteer Coastal Defence Flights. probably a bit like the RAuxAF I suppose. It seems that operational activities of these Squadrons were more integrated within the RAF whereas those involved in No 1 Squadron always saw it as a major stepping stone to a totally independent IAF and country. O course, following the catastrophic events of partition, many of the members of the IAF would have ended up in the Pakistani Air Force, shortly to be waging war against their old comrades.
* It was at Kanpur that Harjinder found the abandoned wreckage of a Spitfire and, having acquired a PPL some years earlier, he rebuilt it and started to fly it. He was subsequently accepted for pilot training by the IAF and flew to his own Wings Parade in his own Spitfire! I think that this aircraft is now part of the IAF Vintage Flight.