I often see answers to the £100 crossword and also from the 7 day magazine. I have the Mail On Sunday delivered every week but have never found these !
I just checked Sunday Mail and supplements, no 7 day crossword or £100 crossword. I have also wondered about these, maybe it is the scottish or irish edition that get them, not the english.
The "Mail on Sunday" and the Scottish "Sunday Mail" are two totally separate papers. The Scottish Sunday Mail is the Sunday version of the Daily Record really.