I knew a fellow who was shooting an 1871 Mauser for the same cartridge, so it can be done. I strongly suspect that your best route for bullets is a custom mould. You're going to need to slug that bore and order your mould .002 over. Huntington's is the first place I would check for brass and dies. That's very odd brass, but the last I heard basic cases were available to be trimmed and reformed.
What I hear from our Canadian friends is that fees and duties will eat you up, but it can be done if you must. Best to get everything in one package to hold down on those costs.