That particular pattern may be discontinued. But you can probably find the same cloth, either with a plain, or a different pattern.
I suggest you try all the usual fabric stores, JoAnn's, Hancock's, the local cloth store where all the old ladies go, and look for the sime KIND of fabric. Same weave, same thickness, same cotton make-up. Bring some calipers. When you find a candidate, hold it to your lips and see if blowing through it feels the same as blowing through your current cloth. If all else fails, ask for help. Tell them, "I'm looking for this exact same kind of cloth, I don't care what it looks like". If they ask what it's for, just say "Guy stuff".
The last time I bought fabric, I lucked out and got a woman helper who's into cowby shooting, but also knew quite a bit about muzzleloading. :thumbsup: