The link you posted is to a replica of a Colt Single Action Army replica. that is not the correct gun.
The type of gun belt you are looking for is called a "safety-speed". You can find them on ebay cheap. That small rectangular pouch you have is a glove pouch. Where modern police officers keep latex gloves they wear when dealing with "less then clean people."
No one in Mayberry has any diseases. So little use for such a precaution. :lol
So, I realize that I'm coming to this thread about two years too late, but I'm in the process of putting together my own Barney Fife uniform (recently put together a pretty good facsimile of the "ol' salt and pepper" suit, and thought I'd do the whole deputy outfit for Halloween.
I'm having trouble locating anyone who sells the had badge. Does anyone know of a place that still sells them?