And finally I got the official Yamaha picture of the Prototype TR1 just in front of the Yamaha Workshops in Japan. Just in time ready for Daytona. Here you can also see that the story in "Cycle World" was not correct. The machine was built in Japan, maybe upon request from Yamaha US, and after shipment to YMUS it was "readied" there for the race.

Yamaha TR1 Prototype, Daytona 1967

You can "click" for a nice large picture. Clearly you can see the standard YR1 front fork with the forkshrouds still attached!