Now you can make a matching set.
Step 1: Mark the Center
Step 2: Clamp and Drill
Step 3: Hammer
As you hammer rotate the mandrel and apply slight pressure towards the anvil. The ring will form a cone shape. Continue to hammer until the cone forms a cylindrical ring.
Once you have the ring shape you can continue to hammer causing the ring to expand in diameter. This is where you check it against the finger measurement it's being made for.
Important. As yor move the ring up the mandrel, flip it around. This helps to make the cone a cylinder.
Step 4: Mount the Ring
After you press the ring on the socket, use a nut and bolt and secure it through the female end. The protruding end of the bolt will be used for mounting in the drill press.
Place a smaller coin under the socket while you tap the ring on. This leaves an even spacing to true the edges up.
Mount the assembly in the drill press and spin it round. You will shape the bottom side first.
Step 5: Shape
Spray the 400 and 2000 grit sand paper with water. This prevents the sand paper from getting clogged with metal particles. Again, this gets HOT! And don't breath the metal dust.
Flip the ring as needed. Use polishing compound to buff it to a shine. Now that the outside is nice, time for the inside.
Be careful not to mar the ring. Use the wood clamp to remove the ring from the socket. Flip the ring over and press it back onto the socket. Make sure you use a soft work surface when you hammer the ring on and off. I used the clamp it self.