That is a CB77 type headlight and instruments too. With the crash bars and racks, I wonder if that is a police version? I think Honda made a police version of the CB77, so maybe they carried the bodywork over when they came out with the 350.
traditionally the 1969 police bikes (even the cb750) used cb77 style headlight/speedo combos, however a cb350 would not be a police bike in 1969 because honda was selling the cb750 in that capacity (as well as those little 90cc scooters you can't seem to kill).
cb350 frame with older parts on it. The rear grab rail/signal light holder looks handmade but other than that looks cobbled together.
I would suspect that Honda may have had police models available in smaller capacities for some of the crowded urban Asian market where the 750 might have been too much bike. In 69, the size and HP of the 750 might have been too much of a change. Just speculation on my part because I don't really have any idea at all, but I am constantly surprised at some of the niche models that the japanese factories turned out back then.
the cp77 police model had the speeder speedo. it locked at the highest speed attained, so you knew what to write the ticket for. it was also optioned with no turnsignals. and trick cast aluminum bits were the issue. that bike has turnsignals, so its a post 68 min. its an early 350 front end with a 350 front drum. its totally a bitsa.
i found this searching the jp yahoo auctions site to see if there were any 350 parts unique to their market. i nearly shit myself when i saw that tank but after looking at it from several angles and comparing it to superhawk photo's i'm sure it's the same tank. that still makes me happy to know they will mount up
i drug this thread back up from the depths because i did some searching and found that this is actually cb250, the only indicators of that would be the side cover emblems which are missing. apparently the 250 sold like this for quite a while all over east asia. or at least all over thailand where i found pages of pictures of restored 250's.
here are a few other neat picts i found on a thai site
cb450 police model