T2219 Camshaft

I pulled a T2219 X2 camshaft out of a 1963 750 Atlas last weekend and am pretty sure it isn't stock.
Can anyone tell me what year and model Norton this cam came stock with? The cam doesn't have any other markings.
Thanks!

web search came up with this thread
http://www.nortonownersclub.org/noc-cha ... /883156339

That is the only thing I have been able to find as well.
I wish it were a little more definitive.