I'm not home to look, but here's my take:
AA, something Express, QF, Imperial Airways,
Varney Air Lines (an early UA predecessor), LY, PK, MX, PA, JL
AZ, EI, LH, Handley Page, MS (EgyptAir), RG, "NKYK" (
Nippon Koku Yuso Kenkyujo),
Air Union (AF predecessor), ?, SA
Colonial, AY, Florida Airways, AF, SK, AV, AI, SN, NH,
National Air Transport
SR, UA, OA, Los Angeles Airways,
St Petersburg-Tampa Air Boat Line (first scheduled airline), CO, TW, Boeing,
Aeromarine Flying Boat Service, ?
AF, Air Ceylon, DL, BA, SU, CA, IB, AR, KL, NW