Hi Colin
Thanks for your post.
1. Date of Arthur Watts desertion
It's good to have the actual date of his desertion 21 June 1861 in Auckland, rather than my speculation that he might have jumped ship in Australia. It solves a long-standing puzzle I have wondered about.
2,The voyage to New Zealand
I am puzzled by your statement "Fawn sailed 12/11/1859" (I assume you have used British rather than American practice, and this means 12 Nov 1859). It may be that this was the date that the Royal Navy commissioned the ship, but if had left for NZ then, it took an extraordinary time to reach New Plymouth on 23 July 1860 (about 253 days), even allowing for "touching at Madeira and Ascension", putting into the Cape, and the two weeks or so it spent at Sydney. Sources here say that Fawn sailed from Portsmouth on the 21st February 1860, hence my comment that Arthur sailed to NZ in 1860. Voyages were considered to start when the ship left the British port.
The usual length of a voyage Britain to NZ at this time by emigrant ships (non-stop) was about 100 days. Ship arrivals were eagerly awaited, overdue ships were a cause of concern: "HM screw sloop Fawn .....now 106 days from Portsmouth" (New Zealander 6 June 1860 p2) ;"There is no news at Sydney either of HMSS Fawn or the Niger" (Daily Southern Cross 26 June 1860 p2). Fawn arrived at Sydney on 1 July 1860, and left for NZ on 16 July. So for me, the voyage was entirely in 1860.
3.Identity of the Henry Newson drowned at sea on HMS Intrepid 1858.
Have you been able to confirm that the above Henry Newson was definitely the Henry Newson from Felixstowe Ferry?
Beany7143