I purchased these same bulbs and I do not believe they are Satin Slippers. The Lily Register lists them:
Inside soft pink over cream, with a frosty white throat, outside dark rose pink; brown spots over half of each petal; nectaries greenish; pollen brown. Fls l4Omm wide; petals 70 x 30mm, margins slightly ruffled, tips strongly recurved. Lvs alternate, 100 x 8mm, dark green. Stems 1.2m, green, with up to 58 well-spaced fls in a large inflorescence. Midseason.
Mine didn't have enough spots or a white throat. I wrote to the supplier and got no response.