First time I have seen one of these on the street for about 20 years.
Its a real bitsa. I suspect it started life as a TS400 (the tank paint is a 1973 K series) but its had lets say "extensive" modification including the TM side panels. Check the lower shock mounts which I assume are to compensate for the exhaust. You can see the original lower mounts still there.
That the RD400 donk? Auto-oiler and all that?
Looks to be in neat shape!