To make the monogram, I would take the picture you have of it, crop out what you don’t want, and enlarge the monogram to the size you need and make yourself a paper template. You can then use an Exacto knife to cut it out. I’m not sure how to get the texture you are looking for, but you can look in the craft section of Hobby Lobby or Michaels (if you have one), there is a wide variety of embossing mats there. For the chain, I would roll out very thin ropes, or use an excruder if you have one, make a small circle with the thin rope, and join them together like a chain. Hope I could be of some help
Toni, Pennsylvania, https://www.facebook.com/WhiteCraftyCakes
