In what is believed to be one of the first tragedies of the Easter Rising, four days later radio operator Con Keating, of Renard, Cahersiveen, along with Charles Monahan from Belfast and Donal Sheehan from Newcastlewest, drowned when their car took a wrong turning and went off a treacherous pier at Ballykissane near Killorglin, on the night of April 20, hours before Roger Casement was being brought ashore at Banna Strand just miles away.
Con, who was from a strong nationalist background, had joined the Irish Volunteers on October 25, 1914. The party were on their way from Dublin. The driver survived.
The medal, awarded to him posthumously, along with his volunteer belt, had been in the safekeeping of his nephew and namesake who lives in Australia.
The objects are being given on long-term loan to the museum in Tralee which is building up a collection from the period.
Mystery had surrounded the deaths for years, but it is widely accepted their mission was to seize wireless equipment from Valentia island, then an international radio and telecommunications centre.
The plan was to set up the radio equipment at Ballyard, Tralee to contact the German arms ship the Aud, which Roger Casement was attempting to bring into Kerry. The Aud was being tracked by British intelligence which had most likely intercepted radio messages to the German ship from Washington.
Con Keating, who trained as a radio operator, knew the area well.
Dr Griffin Murray, collections officer of Kerry County Museum said the medal and belt will go on display shortly.