Great score, must be the only 2 Fireballs in NZ surely?
If you are looking for a NOS backglass a couple of people offered one on this thread.
https://pinside.com/pinball/forum/topic/wtb-bally-fireball-backglass
As mentioned on that thread also are repros from shay, thay are a superb repro in every respect except the only thing is they are screened on plexi & not on glass, but I had one of these before & was more than happy with it. They do ship internationally (not cheap though).