Well Known and Active Website User
I would not create a hard and fast rule, I was just noting that on many of the original photos of Lightnings and Flashes that smooth oil lines were used. I was reacting to how firmly the default position has been that herringbone lines came on all Vincents. I don't think this was the case. However, I am not certain that there are enough original photos of Vincents, with good visual detail of the lines to make a conclusion either way.