you've picked an awkward one there!
Whilst with Naval 3's "A" Flight, it was probably PC10 upper surfaces,with one or two vertical white bands (probably one) behind the fuselage cockade and clear doped fin with the Sopwith "advert" painted on it. This is supposition based upon the other machines in A Flight.
Can't help when it went to Naval 9, as far as I know there are no clear photographs in existance of a Naval 9 Pup. I have one incomplete Pup hiding behind a Naval 9 triplane, and from what can be seen it was PC10 on all upper surfaces. There is also a photo of a pile of wreckage which purports to be a Naval 9 Pup, again PC10 on all upper surfaces.
When with Naval 11, it was almost certainly in standard condition, PC10 on all upper surfaces. Naval 11 was an operational training squadron or "Pilot's pool", they didn't go in for fancy markings.
There are several photographs of Casey around, unfortunately I don't have one - should be easy to acquire though. Pinder, never seen one, if you have his RAeC licence number, there's a good chance the RAF Museum at Hendon can oblige. Brown, never heard of him
Bit of a disappointing answer really, sorry!