It's not one of the prototypes......if you look carefully it has a rubber top brake hose, it also has metal shrouded plug caps, a finned oil filter housing, horn on the right side and as mentioned, the UK rear light unit.....it certainly looks like a UK bike, all the first ones got the high handlebars....... it also has the later style Honda mirrors, not the 'nutted' version usually fitted to early CB750s.
If it's a UK bike it can't be June 1969 though because UK versions didn't exist then.
The first UK market bike was manufactured on the 22nd October 1969 (fifty years old this month) and was on the road in the UK in January 1970, so my guess is, he is one year out and it's the 1970 TT. I wonder why the clocks were missing..
In the bottom right hand corner is another bike with a metal shrouded fork leg in what looks like brown....I don't know the range well enough, but that might date it.
Mick.