Yes, there are a lot of blanks, and I have had little time, or information, to dedicate towards doing more research on the NZ fleet. I believe that NZ my have only had 1 or 2 workshop vehicles, but I do not have the chassis number of the one at the museum, and my last planned NZ holiday never happened as there was a bt of a mess there at the time from earthquakes. I went to Fiji instead.
So, we know they have at least 1-2 workshops, I believe 2-3 ambulances and quite a few skippy shorties.