Here is a classic Doomwatch tv listing from the Australian TV Guide The Gympie Times. Doomwatch is listed in 1972 which would have been a B&W 16mm print. Interesting, that it appears to be on at 9.20pm reflecting the same time as the UK showings and also the name is split DOOM WATCH.
A huge thanks to George Rainey from Australia for getting in touch with me. George kindly posted these to me via Sea Mail on the 11th June and I just got this and a few other goodies today!