My dad got awarded the Royal Victorian Medal as a WO2 in North Africa in 1943 for arranging security for the king. He got the ribbon by hand from HM at the time, and a week later his commission came through. Had he been commissioned before the royal visit he would have received the MVO, which unlike the medal, carried with it post nominal letters.
After the war he returned to his job in the AA, who always quite incorrectly referred to him as "Supt M. Bloggs, MVO", right up to his retirement in 1968, as they thought it rather good to have a member of staff with post-nominal letters. Total snobbery of course, which amused dad, but he happily played along with it!