That's bad luck Nasher, particularly at this time of the year when a summer full of riding stretches ahead.
But I guess it could have been worse.
I'm drawn towards thinking that the starter sprag failure is likely to be linked.
Maybe there has been some damage to the alternator as a result ?
And perhaps that resulted in overcharging and thence overloading of the reg/rec.
Here's a short vid that I found which may be helpful.
https://www.youtube.com/watch?v=2CiMH_KscV0
But on another tack ...
What's the condition of the usual culprit .. the yellow wire connections from alternator to reg/rec ?