Ok have the photo but left it in my brothers glovebox this evening but on careful examination DD you are right the right one is the alternator on my 68 vb10.
I thought it was the left but definitely the 68 and 70 models I have are the right.
Im thiking the left would only fit the later cast iron brackets on the mid dizzie engines 1975 ownwards?

edit found one
http://www.gumtree.com.au/s-ad/burnie ... rs/datsun-1000/1002096829