Bruce..from your serial number I think it is a 73 manufactured in Oct.. the three numbers after the 54 is the year and month. the numbers after that are serial numbers which were sequential. So it makes sense that if it was one of the original Australian Ktms it may not arrived in the country until early 74.. although per other comments from the experienced guys, the frame, tank colour etc give it away in any case.
Id be interest to know if the tyres are original and what brand? Also are the levers mangara ?
If ever the original import papers come to light for the first lot of Ktms that arrived in the shipping container back in the day, it might confirm the actual original Australian versions which would be interesting. I would assume it would also give those particular examples some "value"
I have some papers for my 77 model as it was a GS and the guy in townsville who I bought it off for some reason registered it at some point.
I share the view that they should be more valuable then the market is willing to pay, but perhaps like anything, its only worth what someone else is willing to pay you.