Charles Dance could be terrific, though he's already 77.
Others:
Jeremy Irons (75 — too old?)
Daniel Day-Lewis (67) (good luck)
Sean Bean (65)
Hugh Grant (64)
Ralph Fiennes (61)
Hugh Bonneville (60)
Daniel Craig (56)
Could be good now, but probably too old:
Bill Nighy (74 — but seems older than Dance and Irons)
Ben Kingsley (80, bald)
Michael Caine (91)
Terrence Stamp (86)
Malcolm McDowell (81)