Source: Per research by 160th Battalion Facebook Group. Confirmed served with 18th Battalion.
Family Search: When Private Sidney Oscar Plowright was born on 9 October 1894, in Vespra, Simcoe, Ontario, Canada, his father, George Plowright, was 33 and his mother, Caroline Pattenden, was 27. He married Ruby Elizabeth Nixon on 4 October 1919, in Lucknow, Bruce, Canada West, British Colonial America. They were the parents of at least 2 sons. He registered for military service in 1916. He died on 9 May 1969, at the age of 74, and was buried in Greenhill Cemetery, Lucknow, Bruce, Ontario, Canada.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 