I don't think a crossing back to tenebrosa would fix those narrow, curled petals, but it sure would make a beautiful lip! And the cross using a nice aurea tenebrosa would be exquisite--it would positively fluoresce!
I'm really surprised this isn't a more popular hybrid. It indubitably has its faults, but it's an incredibly vigorous (yet compact) grower even in the oppressive Mississippi heat and has such showy, unique flowers.