It is in the Wills and Probate listing, Dawn, and it is 1946. It is the only time I can find any reference beyond his birth cert on ScotlandsPeople or Ancestry to him.
In 1901 William F. Nevin is at home (father Charles F. Nevin head of household)- 12 Newhaven Rd, Leith. In 1891 the family is at 55 Junction Street, Leith.