http://imslp.org/wiki/The_Dance_Music_o ... Francis%29 O'Neill's The Dance Music of Ireland, the "bible" of Irish music. (Irish)
http://imslp.org/wiki/Harding%27s_All-R ... Various%29 Harding's All-Round Collection of Jigs, Reels, and Country Dances. (Old-time American)
http://imslp.org/wiki/Category:Fraser,_Simon The Airs and Melodies peculiar to the Highlands of Scotland and the Isles, aka the Simon Fraser Collection. (Scottish)
https://archive.org/details/skyecollectionb00macdgoog The Skye Collection of Reels and Strathspeys (Scottish)
http://fiddlehaven.net/ryans-mammoth-collection.pdf Ryan's Mammoth Collection, 1050 Reels and Jigs, 1888 or so. Later republished as Coles 1000 Fiddle tunes. (Old-time American)