Arrived at Palma in 1985, alongside was Airways Cymru One-Eleven G-WLAD. Tracing its details later, I found it was none other than onetime British Eagle aircraft G-ATPI, on which I made my first jet flight in 1968 on Liverpool to London, just weeks before Eagle went under.
Doing a Google search to see G-WLAD's actual dates, about the third entry was actually a thread here 9 years ago all about the aircraft, seemingly by the same participants (including self), so instead of recollecting it all again and likely being inconsistent I'll just link to it
G-WLAD British Midland and Airways Cymru - PPRuNe Forums
Airways Cymru never seemed to get any high-utilisation holiday flight series, and just worked with lesser sets of flights and ad-hocs. Regarding One-Elevens out of BRS/CWL, I think I recall in the early 1970s Cambrian were of course there, and also Court Line in 1973-4, in one of their less-common actual basings away from Luton, for Clarksons.