There are two Greaney's listed in the Irish Newspapers for 1941.
John Greaney, Mallow, Wireless Officer Irish Examiner May 12
J Greaney 4 Sir John Rogerson's Quay Fireman Irish Independent Sept 20
both merchant navy, nothing about burial of either.
Given when they were in the paper are you sure the Greaney who died May 5th was the fireman?
Ah the Wireless Officer's ship was torpedoed in March.