i think Eagle may have done some ad hoc occasional flights from LTN but not many
the British Eagle failure in late 1968 lead to Lunn poly/Everyman urgently needing summer 1969 IT contracts which is why Dan Air quickly set up the LTN base with 2, then 4 1-11's to fly for them, plus G-AZED came along later making 5 units.
losing LHR as a base was a knock for the holiday company as LTN was seen as the ''poor relation'' for IT charters (no disrespect to my LTN colleagues)
Clarksons had Autair 5 1-11's and Monarch had just started up for Cosmos
Thomson SkyTours/Riviera had BY Brits and 2 B732's new in 1968
Channel 1-11's and Tridents were flying for Lyons holidays but mainly from STN but they did fly from LTN too