Re the EI 1-11 IT holiday charters - The chaps on the EI FB group say they did DUB-Palma Rimini Menorca Ibiza in the early years at night...
quotes:
When the One-Elevens first arrived there was an feeling that jets were more expensive to operate than their turbo-props (Viscounts), so there were minimal charter operations. Then it was noticed the cash operating costs per seat were less than for Viscounts and so some night charters were operated. Then the B737-200 came along and cost not much more to operate than a One-Eleven in cash terms but had about 113 seats against 74, so nearly all the night charters moved to B737s. This made the One-Eleven even more popular with the pilots.
Ibiza on EI-ANE Dep Dublin 22:00 July 31st 1970 return fortnight later on same aircraft. Charter with Global Travel
If you could get old copies of Joe Walsh Travel/Tours, Blue Skies or Sunbound summer brochures from back then you might get some idea...