Watch List notes:

Elizabeth II, Silver Jubilee 1977, silver medals (2), by Stuart Devlin, crowned bust r., rev. Royal arms, 38.5mm., one mint state, one damaged on edge and surface marking; others also by Devlin, HMAS Melbourne, Silver Jubilee of service, silvered medal, 1980, 40mm.; coins (2): Guernsey, two pounds, 1986, proof; Mauritius, Royal Wedding ten rupees, 1981, except as stated all much as issued (5)
Devlin marketed commemorative paper knives / letter openers to honour the Jubilee which used the medal as the finial. It would appear that the damaged medal was from one of these.