Back to the OPs original question, Delta operated both the DC10 (-10) and the L1011. Later they merged with Western Airlines and acquired around 8 or 9 DC10-10's in that transaction. WAL had previously operated a single DC10-30 (former AZ aircraft) and pretty much dedicated to a couple of Gatwick, NA routes. I believe DAL was the largestt operator of the L1011's back around 1990. Great airplane!