With the exception of swashes and some details on /G it looks (a lot) like Cheltenham Ultra but I can't find any Cheltenham variation with swashes... I don't know. Modified?

Cheltenham Ultra with modifications was the best I could come up with as well, although I could swear I've seen this 1970s-inspired look before.

HAL-Highs and Lows is an Australian streetwear brand (est. circa 2005), and there does seem to be a complete alphabet for these characters, based on other visuals/tag lines I found.

Any Australians out there who can enlighten us?