What Ed said. As a collector/accumulator, I too have one of these buckles that was probably purchased on eBay. When you collect items besides the guns, you will find many fakes and when you start out it is tough to know the real from the phoney. Especially some of the older patches that are rarer and have grown in value. Once any collectible becomes valuable the fakers begin to see dollar signs.
At one point, I gathered all of the faked S&W items that I had acquired in one pile and there were quite a few. One of the big sellers at gun shows is the S&W watchman or guard badges. You get suspicious when you see that the seller has a box of 100 of them. That is usually a dead give away. Unfortunately when sold one at a time on eBay it isn't always possible to see that.
What I learned was when someone was offering a "rare" one of a kind anything, I would look at his recent feedback and see if there were prior auctions for 20 of the same "rare" one of a kind item. If so, you probably have a good clue that it really isan't so rare after all.