Although I easily found their marriage in Merthyr Tydfil, Glamorganshire in 1930, and there are Medal Index Cards soldiers with Italian sounding names and given name of Pasquale there doesn’t appear to be any record of him serving in the British Army during WWI nor is there an entry in the 1911 census.
It’s the same for records at the National Archives of the Royal Navy, 3 sailors with Italian names, born in Italy but no Pasquale and no records at all for the Royal Naval Reserve, RNVR or RAF.
Nothing in either WWI or WWII Merchant Navy medals at the NA and no Alien (Immigrant) registration card 1918-1957.
http://www.nationalarchives.gov.uk/records/our-online-record... With the Canadian WWI soldiers database again several Pasquale’s but no Tuozzo.
http://www.bac-lac.gc.ca/eng/discover/military-heritage/firs... Using the LDS Familysearch web site
https://familysearch.org/ there is one draft registration record for a Pasquale Tuozzo, he was born 27 Feb 1875, Italy, registered Fayette County no 2, Pennsylvania, USA.
He may have changed his name before or after WWII that could explain the lack of a death certificate; what occupation did he give on his marriage certificate?