Bruce, I tried the vegas thing and I tried the island gig. Nope. I could to go to Africa hunting for what this wedding is costing.
The only thing I know to call that leather peice is a frizzen cover. The problem with black powder is the dang stuff wants to absorb moisture and turn to soup. Sealing the pan edges with beeswax can help and mixing the 4f pan powder with a product called oldbones can extend the life of the priming powder but I choose not to prime the pan untill ready for a shot if its misting or snowing out. Heavy rain and I stay indoors. One mor tip, drill out the factory barrel flash hole, several drill bit sizes, for better ignition.
On the Fly, I like your dad's choise on muzzleloaders.