I'm missing 13 (1896, 1897, 1899, 1904, 1907, 1909, 1913, 1918, 1940 w/1945 insert, 1942, 1954 and 1958). A have two that are reproductions, and a couple that are part of a Hawkins Catechism of Electricity. I think Mike Holt is missing 8. And even the NFPA has 5 original issues that are AWOL. I know of no complete set, but I'm not the authority on the matter and there may be a complete collection of originals out there.
There's a seller on ebay that has a source for many old ones. We've corresponded about possibly getting together sometime and putting our collections together to create a complete original set just as a photo op. But there's about 1200 miles between us.
Some years aren't actual updates, they were merely the 'current' edition printed the following year. The standard 3-year cycle wasn't adopted until 1962.