I can't see any pictures but presumably it's the yellow/blue one on Pedal Room.
I think you identified it correctly on there, the 178 means first bike of 1978.
JR is the riders initials which would be Jan Raas.
No reason to think it wouldn't have been built by Jan le Grand because Jan Raas was the star rider and the Teams bikes were his responsibility.
I can't see any pictures but presumably it's the yellow/blue one on Pedal Room.
I think you identified it correctly on there, the 178 means first bike of 1978.
JR is the riders initials which would be Jan Raas.
No reason to think it wouldn't have been built by Jan le Grand because Jan Raas was the star rider and the Teams bikes were his responsibility.