Had another look tonight.
Tested the battery:
12.7v bike not running.
At idle it dropped to 11.7v
When reved (3k rpm before bogging) it was anywhere from 12.7 to 13.7v
I put the battery in my bike and it was sitting at 13.7v (which is good in a rgv)
So I guess that suggest the rectifier.

Won't be doing any more work on it as it well over due for a top end rebuild