Here's some ideas...
Robert Blake - probably best known in the UK for the TV show "Baretta", aged 71 and currrently standing trial for the murder of his wife.
HRH Duke of Edinburgh - aged 82, health allegedly giving some concern.
Dick Cheney - US VP, health probs for some years now, under pressure.
Dick Clark - long time host of the New Year show on US TV, aged 75 and currently hospitalised after a stroke (may not be well enough known in the UK)
Any one (or more) of
Bruce Forsyth
Ken Dodd
Max Bygraves
Bernard Manning (surprised he's made it this far)
Former TV wrestling stars Mick McManus and Jackie Pallo, both pushing 80 (although McManus looks in great shape at 77).
Long-time Scottish politician Winnie Ewing (must be close to 80)