Danny,
Re topgas's second picture...
While we're waiting for the full answers to your questions, perhaps I could shed a little light on two of them:
What was the gift?
The gift from the Nizam was a complete squadron of Airco DH.9As.
They entered service with 110 Sqn around June 1918.
What is the significance of "No 6" ?
That inscription panel displayed in the frame would have been cut from 'Aircraft No 6' of that gift before it went to the boneyard.
Looking forward to topgas giving us the full story.