I am still keeping about 10 of the seedlings resulting from the L56-1 X Basye's Thornless cross, two are shown below. The first of the two is quite fertile as a seed parent and there are several new seedlings coming from it this year that will be blooming soon for the first time.
Basye's Thornless conveys cleanliness (good resistance to both black spot and powdery mildew), and fewer thorns to it's offspring. Also, as seen in other seedlings of it in this link: Winter, Spring or Fall?, it frequently produces seedlings that give added interest when the plants enter dormancy, since many of its seedlings produce colorful hips and striking fall color. If you haven't already tried it, Basye's Thornless is definitely worth considering as an addition to your mix of rose parents in your rose breeding program.