Concerning the lightweight and heavyweight cars, I cancars were referred to by some at the time, as "streamlin give my recollections from the early to mid 1960's. The lightweight ed", and the heavyweights simply as "old".
IC had mainline trains plus a couple that ran from Chicago to Council Bluffs IA. Also there was a branch from St. Louis that joined the main at Carbondale, where the cars were set out, and coupled into the mainline trains. There was also an overnight run that went from St. Louis to Memphis.
The Chicago to IA trains were The Land O' Corn and The Hawkeye. The Land O' Corn was the streamliner. I never saw or rode either of these trains, so I'm drawing strictly from my remembrance of timetables of the era. I don't recall the numbers or consist of the trains. The Land O' Corn was generally considered the equal to The City of New Orleans and The City of Miami prestige and service wise.
The Chicago-New Orleans trains were as follows:
No. 5-6 The Panama Limited, all Pullman no heavyweights, with an observation car.
No 1-2 The City of New Orleans, all coach no heavyweights, with an observation car
No. 3-4 The Louisiane, mostly heavyweight coaches, with a couple of Pullmans, maybe a few streamlined cars mixed in
No. 8 The Creole, primarily a mail and express train with a few heavyweight coaches, only ran northbound in the daytime
No. 25 The Southern Express, southbound equivalent of The Creole, but it ran on an overnight schedule.
Chicago-Miami
These trains left the main at Fulton KY, and traveled over IC tracks to Birmingham. At Birmingham, they continued through Georgia and Florida on The Central of Georgia, Atlantic Coast Line, and Florida East Coast. I don't recall where the transfer points were between each road.
No.52-53 The City of Miami, coach and pullman streamliner, with observation car. During the winter season, it would sometimes have dome cars. But I don't think the domes were an ongoing thing, and maybe were a short term experiment for a few years. I recall reading somewhere that they were leased from the either the GN or NP, and were repainted every summer when returned from the IC.
No. 10-11 The Seminole, primarily heavyweight coaches, with a couple of Pullman's. Moreless the Florida version of The Louisiane. I think it terminated at Jacksonville, but I'm not sure.
St. Louis-Memphis
No. 15-16 The Chickasaw, primarily heavyweight coaches, It also carried a Pullman or two, that would be set out and coupled into the southbound Panama Limited at Carbondale. The Chickasaw's and Panama's E's did the switching. There was no yard crew nor engine at Carbondale.
This is a snap shot of a young boy's memory in the 1960-65 timeframe. There could be things I've left out, or not remembered. I was quite a rail enthusiast in those years, as was my Father. I became a teenager, and lost interest in what happened in the years that followed leading up to Amtrak.