Abby there's an early "Rising Sun" text in the bound copies of Robert Gordon's transcripts in The Library of Congress Folklore Archive, Vol. IV, #925. I did not note the date on it or copy the song. I trust you know how to contact them via e-mail or can find out (click on from my homepage and search from there). However, bawdy songs collected by Gordon are in a separate set that are not available to the general public, and you might ask them to look in that, too (I've never seen it, but my recollection is that they had an index to it.)