Dominick,
You can't be too careful with old weapons. Down here is OZ (Australia) I was asked to repair the stock of a flintlock rifle that had fallen from the wall of a historic mansion, allegedly been there for 150 years untouched.
As old safety habits are hard to break I checked the bore with a ram rod and came up short. Using a self tapping screw on a rod I removed the ball and a good sized solid block of 150 year old black powder. I lit the powder for the trustees when they came to visit and inspect the restoration, it burned very nicely thanks very much.
I was asked to check every other firearm in the building, but that was the only one left loaded by the long dead 'lord of the manor'. It was just sitting there quietly waiting for someone to stuff up, lucky it wasn't me.
Lovely old Gun and carriage if I may say so, I hope you get her firing soon.
regards
Shooter 2