Pro Tip: Paint the domed disc ONLY if the cuff will not get hard use. Paint may chip off if it is tumbled. Otherwise, texture it or leave it smooth.
Cut a 1" disc from 24 gauge copper sheet. Sand the top of the disc to create "tooth" to make it easier for paint to adhere to the metal. Dap the disc until it fits into the brass piece created in Step 4. Go back and forth between Step 4 and 5 until the fit is a bit loose, as shown in the photo. It tightens up a bit when the cuff is formed (see Steps 36, 37 and 38). Optional: Dome a coin of a similar size. The hole size may need to be changed to fit the coin if a different size is used. If a thick coin is used, such as the coin here, the outer edge may need to be sanded off at the domed angle after shaping for a better fit. Note that coins are very hard and can damage your tools so may need to be annealed to dome them. However, check the metal content as during heating they give off toxic fumes.