"Ashokan Farewell" was published by Mel Bay on 1 January 1983. Must have made Ungar a fair bit in that form, before the Civil War royalties started rolling in. I don't have that print collection but I doubt it varies one little bit from what all the thousands of Ashokan fiddle camp participants played as their final number over the next 40 years.

Print doesn't have to be used that way. Almost all the standard ceilidh band repertoire got into it from a paper source; the selection of good tunes was usually very quick, folk processing didn't come into it. Think about "Staten Island"; Desert Dancer and I had a discussion about it here where we pinned down its origin to the aftermath of the Battle of Long Island in 1776. It had to have been created for a dance assembly in New York celebrating the British triumph (which later became one of history's greatest examples of snatching defeat from the jaws of victory). Those repeated C naturals are British cannon shots smashing into the American forces (play them with feeling). That tune was in print in the second volume of Aird's collection in Glasgow in the very early 1780s. It was an immediate success and has been played pretty close to the way Aird had it ever since. There was no time for it to get refined by an extended process of oral transmission: some danceband leader in NYC thought it up, somebody passed on to Aird in a notebook with the regimental marches used in the battle and Aird just engraved the whole lot with zero effort at arrangement. It got more variation than Ashokan Farewell (somebody tried to lose the C naturals and retitle it; posterity told them to get stuffed) but even with no known composer shepherding it along the way Ungar does, it stuck.

One example of a tune that did follow Steve's model: "The Dashing White Sergeant". If you look up Henry Bishop's original song you will notice (a) it's rather crap and (b) nobody could ever dance a reel to it. I don't know how it got into its modern form (as in Kerr, late 1870s) but the change was drastic and much for the better.