I found some literature from about 1974 that lists the Service Classificiations and additive packages for motor oils to the SE level, with the older API 1509 classification in [ ]:
SA- [ML] - Gasoline or Diesel Engines for light duty (speed, loads and temperature operation); may contain pour and foam depresessants.
SB- [MM] - Gasoline Engine oils for moderate duty requiring slight additive treatment for oil oxidation, bearing corrosion, and scuffing (EP). Evaluation Tests: L-38, Sequence IV.
SC- [MS] - 1964-1967 automobile warranty engine oils requiring more protection additives from high- and low-temperature sludge deposits and varnish, wear, rust, deposits, oxidation, and scuffing. Evaluation: Tests L1-, L-38, Sequences IIA, IIIA, IV, and V.
SD- 1968-1971 gasoline automobile and truck warranty oils satisfying Service SC, but with more (additive) protection from high- and low-temperature sludge deposits and varnish, wear, rust, deposits, oxidation, and scuffing. Evaluation: Tests L1-, L-38, Sequences IIA, IIIA, IV, and V, VB, and Falcon.
SE- 1972 gasoline automobile and truck warranty oils, satisfying Service SD, but with more (additive) protection from high- and low-temperature sludge deposits and varnish, wear, rust, deposits, oxidation, and scuffing. Evaluation: Tests L-38, Sequences IIB, IIIC, IV, and VC.