Alarm in the 33 is a Cyclops Paralyser 785 so this siren should do the trick then I guess. (Looks the same)
I'll just trace the existing wires and hopefully the colours will match up. (Orange, Red, Black & Brown)
and to try fix the original issue, I'll try to install it in a better place so the Siren is not so Muffled.
AudioTech in Tuggeranong seems to be the only Zylux Dealer in Canberra according to the Googles...
I actually rang them and they said for me to take it there, they will likely have to order in a dongle, scan the code from my existing one and put it onto the new one.
(hopefully this will not cost me assorted limbs)
Thanks again for your Help Mr Rogers.