Regarding HKS Speedloader pouches...
Speedloaders pouches came in two sizes in the old days. There was one for the medium size speedloader (Python, K-L frame S&W, Ruger SS/GP) and a larger size for the N frame S&W. Don't know whether HKS ever made it for the smaller J-frame, but this doesn't preclude some other maker/mfg from having done so.
BTW, we use to wad up toilet paper and stuff them into the bottom of the cases. This reduced the rattling sound when we patrolled.