Alan,
There is another nepalense hybrid on the market - 'African Lady'. The background on this one is not as clear.
Your father had bred & sold a lily by the name of 'Oriental Charm' that was registered as L. speciosum var. rubrum X L. nepalense. Do you know if your father had other hybrids between Orientals and L. nepalense?
I am also very interested in the Oriental x L. nepalense crosses.
Patrick