Via Whatsapp, Raoul Coetzee suggested it is at Mt Stromlo and shows the 50-inch telescope.
I contacted MSO and Brad E. Tucker (MSO, ANU) confirmed that it is, indeed, the 50-inch Melbourne Telescope at Mt Stromlo, probably from the early 1960s.
Matilda Vaughan (Engineering Curator at Museums Victoria) also confirmed the identity, writing “Yes that is definitely the 50-inch telescope dome at Mount Stromlo, circa 1960.”
This telescope has an absolutely fascinating history, more so if you’re interested in deep-sky observing. It began life as the Great Melbourne Reflector in the 1860s “devoted chiefly to a revision of the Southern Nebulae observed by Sir John Herschel at the Cape of Good Hope in the years 1834 to 1838.”
You can read more about this instrument and its early work in this 1885 publication: Observations of the Southern Nebulae made with the Great Melbourne Telescope from 1869 to 1885. Part I. Melbourne.
The disastrous fires at Mt Stromlo in 2003 gutted the telescope. However, it is now being restored by staff and volunteers! You can follow their adventure via Twitter at @GMT21stC and on their website.