WW1: Thornycroft truck-mounted 13/16-pdr AA gun

I have found your web site a most interesting source historical information and now have a list of further places to visit about this country looking at areas an objects of our history.
 I have a particular interest in the history of the WW1 period, with particular interest in the vehicles used. This has been founded on having the remains of an early truck, and with much research it does appear to have been originally  war department  property (British).  Features of this truck (Thornycroft J) indicate it was designed to have a 13 or 16 pounder anti-aircraft gun mounted on it.
With the forthcoming centenary of WW1 I would like to be able to restore this vehicle back to this format.
Does any one know of  such a gun in NZ or Aus  as a display piece, or remains of one, or plans from which a replica/ mock up could be constructed.  The gun set up on the Thornycroft  at the Imperial War Museum. Duxford,  England is not original having being built up more recently on a Thornycroft standard chassis.
Any assistance appreciated.
Thanks
Doug Wheeler
Email Doug