I'm not getting back any 'hits' when searching for the surname 'Shorthouse' in the PRONI eCatalogue. The death notices for the couple in 1950 and 1951 basically said 'funeral private', ie. there was no mention of any children or other relatives. Nor am I getting any local 'hits' for the surname Shorthouse in newspapers post 1951.
I can see him in the 1891, 1901 and 1911 England censuses (his age at death must have been understated), he was a Birmingham man, not sure how he and his wife ended up in Northern Ireland, he did have several siblings, if any records still exist, they may have ended up with their children, though I'm not optimistic...