Answering my own question here. Trident - first civil aircraft with Autoland? Seems not. Below from FS web.
Trident G-ARPB carried out the first Cat 3B landing at Heathrow (28L) on 4th Nov 1966. At this time, she had done some 1500 auto-flare landings and many of her operating systems were already ARB approved (Cat 1). The Trident 1's were cleared for duplex Cat 2 auto approaches in 1968 with full Cat 2 Autoland approval on 7th Feb 1968. Triplex Cat 2 Autoland were cleared in Sept 1968. However, full Cat 3A ops were not approved until May 72 with Cat 3B following in 1975.
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The Caravelle had its first autoland test ( although in Cat 2 ), in 1962 and the first autoland in the US in 1964, and was certified to this standard in September 1964. First passenger airline to be authorized to do Cat 2 auto landings was Alitalia, in spring 1966. Cat 3 certification came in early 1967 and by that date, the Caravelle already executed 10.000 automatic approaches with 3500 that included automatic touchdowns as well.
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United used autoland with Caravelle in 1964 already and Aerospatiale did the first successful tests in 1962, but these flights were probably unscheduled ones. However, some things are quite certain: certification dates. According to this paper from Hawker, The Trident was certified for Cat 2 in Sept. 1968, and BEA was authorized to use it in Feb. 1969, comparing to the Caravelle that got Cat 2 certification in Sept. 1964, with Alitalia started using it in spring of 1966. Before the Trident got Cat 2 ( Feb. 1968 ), the Caravelle was already certified ( in Feb. 1967 ) to Cat 3A.