I'm sticking by my first chose which is the high-level El Capitan, which was started in the mid 50's and was economic in that it did not require as many coaches as previously needed for the slightly earlier El Capitan
1953-1956
http://www.trainweb.org/fredatsf/elcap53.htm
1956-1960's
http://www.trainweb.org/fredatsf/elcap56.htm
1953-1956
http://www.trainweb.org/fredatsf/elcap53.htm
1956-1960's
http://www.trainweb.org/fredatsf/elcap56.htm