The bolt face is too large for .350 Legend.
With a rifle and barrel in hand, the gun could be rebarreled in an afternoon.
Find yourself a nice 1885 Winchester for the task. Maybe a rolling block if those suit your tastes.
Your least expensive option is a new CVA break open single shot. I see plenty for sale. Ugly, but they probably shoot as well as the Winchester, Savage, Ruger, and Mossberg rifles I see for sale with this chamber.
An option for the rifle you own is a bolt from Pacific Tool & Gage. There will likely be an unknown wait if there is not a bolt in stock.