Nice research but I dispute the logic of the article.I myself frequently do this sort of neologizing word play. That citation does at least suggest that 'hunky-dory' was in common enough use in 1866 for the author not to see fit to explain its meaning, although it's a pity 'hefty' and 'kindy dusty' weren't explained as these have now disappeared from the language.Edit: and I see below that hunky dory was used in a poem .. It seems that The Galaxy writer had been perplexed by the recent popularity of the the expression, which appears in several publications in 1866; for example, Google translates "non compos" as "not in control" but its translation of the full expression leaves much to the imagination: "Dover hook on the uptake." Origin in post-Civil War time seems to be realistic.The least exotic theory of all, but almost certainly the true clue, traces "hunky-dory" to the archaic American slang word "hunk," meaning "safe," from the Dutch word "honk," meaning "goal," or "home" in a game.To achieve "hunk" or "hunky" in a child's game was to make it "home" and win the game.
There's no agreed derivation of the expression 'hunky-dory'.
It is American and the earliest example of it in print that I have found is from a collection of US songs, George Christy's Essence of Old Kentucky, 1862.