Unfortunately they are common but here goes
Monarch Airlines Britannia Luton to Basel approx 29/5/73 returning 7 or 10/6/73 these are the two I'm really interested in
Dan Air BAC 1-11 Luton to Palma 14/1/74 am returning 18/1/74 PM
This one is slightly more sketchy on dates Britannia Airways B737 Luton to Rimini 3/5/75 returning 17/5/75 Previous research showed one a week but not sure which day. Return was within 5 days after the 13/5/75
I appreciate these will probably be unsolvable but it would be great to find out.
gatman