It works! I think I had a combination of problems - PBP config and a weird breadboard connection issue (I have 4 banks of +/- and when the chip was connected to the far bank the voltage potential between Vdd and Vss wasn't 4.91 volts (my 7805's 5v) - more like 1.93 v. Once I configured the chip with Darrel's code above and move the power connections to one of the other banks I can see the LED fade in and repeat.

Thanks heaps Darrel!