Some of my missing ones are due to either poor blooming or flowers that weren't very attractive. Others due to name changes over the years. Others due to non legal Paphs.
I suspect that breeders don't want to remake ones that will not be multifloral, such as roth X Paph venustum = Paph Bruxellense. There are a few out there such as roth X concolor that I can't afford at the moment. (Krull Smith has been having these on e-bay)
Here are a few of the ones I am looking for:
Paph Garnet Crown (roth x wardii)
Paph Susan Salzman (roth x violascens)
Paph Gemstone's Randschild (roth x randsii)
Paph Marcel Lecoufle (roth x urbanianum)
Paph Jack Fowlie (roth x hennisianum)
Paph Jeffrey Bevis (roth x acomodontum)
Paph Apple-Roths (roth x appletonianum)
Roth x vietnamense