I think you may have a difficult time finding this one. Lucas Light was Hybridized by Betty Fretz, who unfortunately has passed away. I could be wrong, but I don't think Lucas Light was ever made widely available, like in big box stores or major garden centers. Making it more difficult, Betty hybridized out of Canada. If someone did take over her gardens in Ontario, it's hard to get plants past the border.
I want to say I've researched this one, or another one by Betty before, because all this information is coming to my head. If I were you, I would try to contact the Ontario Daylily Society to ask what became of Betty's garden, and if anyone is maintaining her flowers.
Good luck,
Tim