There were no specific watches issued to the UK forces in 1961. At that point they would have been using existing watches (it is possible that the FAA got some Lemanias in 61 but they won't be marked as such). The Hamilton navigators came along in the mid 1960s, followed by the Smiths in 67, then the tonneau Hamiltons in 73, I think.
The only watch specifically marked 1961 that I know of is the Australian-issue Smiths DeLuxe; and they are rarer than a rare thing (9 known, I think).