I might buy child ballads, and also some of the better broadside ballads, on "new-style" broadsides. Ones that tell good, complete and rousing stories without too much sentimentality.

My mentor and friend Kenny Goldstein was a big collector of original broadsides and used to take me to big paper and ephemera shows where he would buy them. A few times he needed one broadside to fill out his collection. He knew the dealer would try to gouge him on the price, knowing he would pay twice what anyone else would pay since that one broadside was the one that would make his collection complete. So Kenny would send me to try to buy it. The very first time this happened the dealer listened to my request and without missing a beat said "you go tell Goldstein to get his *%$% ass over here himself!"

I bring this up only because I think Kenny would love your idea to create prints of ballads, so the idea reminded me of him.