Here's the DoM clasp that you can buy on eBay compared to two original clasps.
You can see the bottom clasp has greater relief (no pun intended!) and thicker characters than the originals. The wider characters also means the overall with of the words is greater than the originals and there is less space between the individual characters.
I also saw that one with the stack of copy clasps. If it went cheaply, it would be a good collector's illustration of the difference between the copies and the real ones - and also to see if there was any difference in construction. Not worth much, though!