From Paddy Tobin - a comparison of 'Cambridge' and G. 'Tilebarn Jamie' - thanks Paddy!
"I plucked a 'Tilebarn Jamie' and propped it up beside 'Cambridge' for comparison. 'Cambridge' seems to have a lighter green on the markings and also on the scape and spathe. The size of the markings is also different. "
Side by side for comparison: Galanthus reginae olgae 'Cambridge' on the left and 'Tilebarn Jamie' on the right.