Andy - Thanks very much for that large format photo file you sent through last night - what a cracker! definition fantastic.
Yes I am positive that is Major Elmslie sitting front row second in from the left.
With the picture enlarged all the ranks are easily determined on the forearms of the front row.
As this file is so big, (and I will condense format a image for the net in the next few days) I have taken a small segment of the front row from the right hand side and reproduced it here below. (Major Elmslie is not included on this side)

I am certain of the identity of three of the men as I am able to compare hat badges with ranks on sleeves and with previous photos ( top of page here
http://www.nzmr.org/wellington.htm )
I can't be absolutely positive about Major Dick and Captain Hastings in this photo, mainly because they are not wearing the 6th MR hat badge - my doubts are hightened because both Meldrum and another officer behind the suppossed Captain Hastings, are both wearing the 6th MR badge - one would have thought, that as Meldrum's "Men", they would have worn the distingtive 6th badge, obviously the badges were available. So I have doubts.
But then, on the other hand, the front row has the C.O. (Meldrum) with Majors Elmslie,Chambers and Wain, all C.O.'s of the 8th, 2nd and 9th Regiments - it would stand to reason that Major Dick C.O. of the 6th would be the officer sitting next to Chambers???
However these two "Probable" officers could possibly be - Major Edgar, NZ Vet Corp attached WMR or Chaplin Major Grant - The Captain on the end could possibly be Adjudant-Captain Kelsall or Quatremaster-Captain Wilkie - all men from Headquarters Coy - but I don't think so - hopefully I can compare images and eliminate these men.