I started a thread on this a month or so ago as OzMick when I couldn't get on the web.
In the end the solution was simple, and there all the time it would seem!
When configuring the Speedtouch DSL connection, Australia IS mentioned, but the three options listed: Arachnet, Speedstream Off net and Speedstream On net do not mean anything. As in they're not ISPs like Optus or Telstra, and that is why I've always highlighted 'Not listed Edit manually' and proceeded thus. That was wrong....
When messing around yesterday with a new install; starting from scratch I began the configure and let PCLOS download some Speedtouch stuff which I now know was the ST firmware and firmware extractor. OK. THIS time - more used to the distro and with nothing to lose - I tried the different options under 'Australia' and discovered that 'Speedsream Off net' defaulted instantly to pppoE which is mostly what's used in Oz.
Basically I entered my ISP details and password, clicked on Advanced and there were already the right VPI/VCI entries (8,35) then followed the wizard to the end ...... and was CONNECTED!
It is indeed a joy to crank up my laptop and in silence - with no need to start generators or switch on inverters or other weird power supplies - watch PCLOS boot up with a tick in the Network applet.
Thanks to everyone who helped with advice earlier, and especially to the developers who set it all up.