That poster was widely available years ago in poster and head shops for about $3. It didn't have the Thiumph logo on it though. It was about 3x4 and was in the series that include many icons from the past, W C Fields, Monroe, Einstien, ETC. If I remember the poster was cut off at the bottom of the handle bars, the Triumph marque on the tank doesn't appear.
Interestingly, there is a huge blow up of this photo high on the wall of the local Harley dealership here in Kansas City.