I did take a look at those links, the starting point of my research on this. What we do know is that Lilium 'Golden Stone' exists and is authenticated. In fact it is a rather popular lilium cultivar.
Lilium longiflorum is the species that our Easter Lily is derived from. They are warm climate lilies and that is likely why their crosses with Asiatic lilies tend to bump their zone up a couple of notches.
