Thanks for the mounting bracket info. I just picked up a Honda CB750F and it had a vintage Vetter Farrinig on it, but the factory head lamp and all the mounting hardware were removed. I was out bid for a factory set of 77' Supersport mounting ears today, on Ebay and was a bit frustrated.
It seems these mounts will work to mount up a factory head lamp. I'll have to figure out out I can mount the turn indicators, as the 77' Supersport bikes have them coming from the side of the headlight mounts.
At least this gives me hope that I can make it work.