Hi Nomad.
I have one, engine No. DA10A 470 with its original GA7 frame. unfortunately it does not have the alternator..., crank, or primary, they were not with it when it came to me.
It has been my daily rider for about 8years, just taken it off the road for a refresh over this winter. I have always presumed it was an ex police bike, the log book says first registered July '66 and it is on a D plate so I assumed it was registered again after leaving police service.
I do wish I had the original parts, since owning it I have got hold of an outer alternator primary and I think I could extend the standard crank, it is the inner primary which is the problem, being bigger at the front end. It does have a slightly unusual battery tray.
Alternator A10 cranks were robbed to make hopped up A65's back in the day.
So really you are still alone.
Chris