If you can’t afford the price of a humble flint perhaps you should find a cheaper hobby. BTW I don’t see any bitching about the price of black powder along with the flint rant.
I'm concerned about the lack of secure attachment of the barrel to the base. And the size of the base seems a little skimpy. Conclusion; Tie it down put some powder in it and a projectile and light the fuse. Take all the normal safety requirements.
BP for home or self defense is just foolish. Get a semi automatic hand gun, take a firearms safety course, learn how to handle it, practice at a range and pray you never have to use it.
Last summer it looked OK with Never Dull but sat all winter in the carriage house uncovered. Now dull and some light corrosion. Not sure about brass or bronze. Pretty sure brass.