There are all sorts of modern interpretations of older paints. And as GP has indicated above. But Nortons had their own enamelling tanks, and it would have just had a coat or 3 of enamel out of the factory. As other posters on the NOC Forum have pointed out, and found colour matches for. I painted an early 1950s dommie in Nortons earlier version of polychromatic blue, a much lighter shade than the Manxman's version. Someone familiar with this type of paint mixed it up for me, he said it was a pearl type of paint ( finely crushed glass ) to give that "polychromatic" prismatic look to it in different lights. Someone in the US found this was about an identical shade that Mercury painted some of their outboards back then. http://ecx.images-amazon.com/images/I/41JBY7X%2Bu1L.jpg This ain't rocket science... But we diverge from Manxmans.