His death certificate records his profession as Hairdresser. As his father was a riveter/boilermaker, I’d guess that his physical health was not good, precluded an industrial job, and he took on a gentler occupation instead.

Louis suspects that he died of Tuberculosis - his death certificate says ‘Ihthisis’ (phthisis is Greek for consumption). He died young, and his death certificate states that he'd been ill for several years, so TB seems likely. Poor sod.