No,
The W1 wasn't the first Kawasaki motorcycle by a stretch. They built a bunch of small 2 stroke bikes years before.
Here in Canada in the early '60's, Canadian Tire carried "The K bikes". If my memory serves me correctly, an 80cc, a 100cc and ... if you were manly enough LOL, a mighty 150cc bike. Depending on the country or market, there were 50cc bikes as well.
4 speeds, rotary valves, stamped steel frames, telescopic forks. I think the 150 was touted as a bit of a touring bike if you can imagine that and it came with whitewall tires and the usual accessories like a luggage rack and really cheesy vinyl soft saddlebags.
Then we got the 250 and 350 rotary valve twins - maybe in '66? Wow, did that ever change things.
The first W1 I ever saw here in Canada was probably '67. I've only ever seen one W1SS - the dual carb model and that was maybe a year later. Went like a scalded cat.
In both cases - the W1 and W1SS, the motorcycle magazines at the time both reported them as BSA's that ... didn't leak oil. Think what the Brits could have accomplished if they'd ever got their shit together.
Thanks for letting me ramble.
A real time machine you have there.
Pat