I remember those well, brought back the sense memory of licking the stamps and putting them in books. My mother got quite a few things with S&H Green stamps. There was one other, seems like they were yellow/orange, maybe gold.
I wonder how the distributor setup was handled. they had to pay to create the catalogs, manage shipping, pay rent on all the retail outlets, and pay the staff, not to mention get the merchandise. The various stores must have paid a fee to give out the stamps, anyone know the details?