Congratulations on your purchase.In my pawn shop travels I picked up a brass shot flask that the measure on the spout is in drams, the store owner gave me a ton of unmentionable type paper hulled stuff that he’s afraid to use so I think I’m able to break those apart for their shot. What about the old felt wads ? Can they be ran through this muzzle loader?
There is very good chance the wads in the cartridges you are going to recycle will fit your barrels. Just don't think you need as much as is possibly inside a cartridge. Most wadding in a cartridge is just space filling! So, you may be able to save some by cutting in half etc.
In a pinch you can simply roll balls of brown paper to form a wad.
BUT! If you shoot in a fire risk area avoid rolled paper wadding. It can smoulder after shooting!
Anywhere around 70gns under 1-1&1/4oz will be useful.
Have fun.