I wrapped the back portion of the photo album to keep the moisture content even while allowing the front of the album open. I applied a bit more water around the ring area (front & back) to start the embossing process.
I started the embossing using a semi pointed tip metal ball attached to an awl handle that I custom made. Once I was able to get a good outline of the rings. I used a trick that I learned from one of Robb Barr's videos. I used a small & medium marble to continue the embossing of the rings. When I had sufficient height, I finished the embossing with a small round modeling tool.
I allowed the leather to rest a bit. While doing so, I prepared some leather mud by using 'leather dust' and rubber cement. I mixed it until it was consistent to oatmeal.
I applied the leather mud to the back of the embossed rings making sure to keep it short of the outlining ring line. Using the plastic spoon, I made sure to compact it to reduce any air pockets within the mud.