Peter,

TWA had -100's & -20's and a few sp's.

I worked for AA for 5 years. All TWA pilots had to go through the AA school to be included under their FAA operating certificate.  Back in 1968, I was hired by United, Pan Am & TWA all in the same week. I went with TWA because they offered me the earliest class date. As your dad will tell you it's all about date of hire. I did OK in the AA thing, except they closed all the TWA bases and forced all former TWA pilots to fly out of STL.

Lou