3:54 Housing markings ???

["62bt7" <62bt7@prodigy.net>]

As some of you know, I rcently acquired the complete 3:54 disc wheel
rearend out of early 1959 HBT7L/1428 sitting in the local Midnight Auto 
Pick-A-Part.awaiting the crusher. The pumpkin is stamped 11/39 = 3:54 
gear set.

Question:
Under the 11/39 is a rather large "S" stamped into the case.
Does anyone know what the S represents ????

Maybe out of, one of the long lost 100S's ???? :-) :-)

Kirk Kvam
San Bernardino, CA