5120R/SSP
and the guide says;
5 = Genuine Stag, Second Cut Stag, Red Stag, or Midnight Stag
These handles are made from the antlers of deer. It is very popular to collectors because of its beauty, durability, and the fact that no two handles look exactly alike. Over the years its availability has been limited and it has been temporarily discontinued several times. From 1972 to some time in the 1980's, Case did not use stag for its regular production. It was used sparingly for a few collectors' sets such as the 1977 blue scroll set, and the 1978 red etched set. Following the 2000 production year, it was extremely limited in its use again because of an embargo on Indian Sambar deer antlers, which were Case's main supply. Since this time, Case has made a few knives from left over stock, and some using antlers from deer found in other regions of the world.
This makes me think that the bailed Peanut was not a 'Regular Production' model. I have seen several bailed Peanuts, individually and in sets from that era that were stag and described as stag. I own some 6.5 Stag knives but I have never purchased a second cut stag knife, to my knowledge. One side of this knife has a slight appearance of second cut stag but the other side is unmistakable.