Thanks Wayno.
I think I have just about exhausted every avenue on internet and not too many parts for 520 remain in oz except for occasional vehicles for wrecking. I hoped that if I widened my search for something compatible (maybe 510) or even 520 left hand drive it might be possible to cut and weld to suit. I will have to keep my eyes peeled on eBay.
Recently motivated to finish my project '66 520 ute after 20 odd years and discovered the wiper linkage has gone walk about from the parts box. Any ideas on how to source one or suitability from alternate model?