Back a few years ago I was in Bob Williams shop, Wind River Rifle Co, in Ft Walton Beach, FL. Bob had a wood crate, about the size of an apple crate, in one corner of the shop on the floor, about 2/3 full of Ballard actions. Told me he had parts for them. Bob closed his shop on Duval St. and disappeared. I do not know what happened to the Ballards but might give you a start to find some parts. I tried again yesterday to locate him, but no joy. I just gave the search a quick look.
At one time Bob made button rifled and cut rifled replacement barrels for single shots and lever guns.