for sure.
it's almost impossible to find a decent 20" barrel right now, and 20" is correct for an old fogey blaster much like the one you got...
You don't have any piecemeal machine shops in the area?
Minx, I know the guy that own Oakwood machine shop
https://www.sbn.com/Georgia/Gainesville/Listing/Oakwood-Machine-Shop/_L1GD2l
He has a lathe, and the experience to do it.
He did a musket, and and ak for a friend of mine.
He can put the exact twist you want in it.