An ancient mechanical totalisator from NSW.
Penka dropped me off at this mecca of dead hardware. Entry was $US15, despite the sponsorship of Bill Gates, and lunch was the same again. The story begins with Babbage's difference engine (with a part of a replica made by a Dutchman on show) and proceeds through wartime computation and Turing's contribution to the halcyon days of big iron (IBM's stretch and so forth) and the time when Cray's supercomputers really were super. My childhood was summarised in a single room (of consumer microcomputers); I didn't see an Amiga 500 (just the original 1000) or the classic Atari 600XL/800XL they had in primary school in Orange. There were several old Apples: a ][ but not a //e, a Lisa, an original Mac. They had a panel of old toy robots, but I expect there is a far larger collection out there in private hands.
Australia's (or perhaps New Zealand's) contribution was a totalisator manufactured by George Julius's Automatic Totalisators Ltd; a part of it had pride-of-place in a perspex box just in front of the entry door in the foyer. There were also some fragments of CSIRAC (I think) of the JOHNNIAC lineage, on loan from the Victorians.