When Elizabeth Corris Gill died in 1957 in Minnesota, there was a notice of her death in an Isle of Man newspaper which said she had 2 brothers and a sister-in-law still living on the Island. I'm confident that the sister-in-law was Christian Kissack Corris widow of her brother Enos.
I'm thinking the brothers must have been John Edward Corris (1881-?) and Robert Arthur Corris (1899-?) but I cannot really find anything of them.
I cannot find John Edward after the 1901 census. Robert Arthur was named executor of his sister Selina's will in 1938. In 1938 he was living in Ballerjoi, St Mark's, Malew and was described as a haulage contractor.
I've looked in Lawson's burials and the records held by Ancestry and the IOM newspapers online at iMuseum (which I think don't have many issues online from the 60s onward). I cannot find any record of death/burial (or really anything else) for either of these two men.

Any suggestions as to where to look?