Pukka,
What a marvelous piece of art. To answer a couple of questions; the flask is a common J&W Hawksley flas of the period. The shot/powder chargers are few and far between, and costly, however, Mike Lea makes them and has them available. I don't know the cost but they are very nice replicas and work well. He can be reached at 614-2914757 in Columbus, Ohio.
Mark