Inner Valve is a brass disk covered with pouch leather. We start with this tool using a fostner bit depression, and a hole through the plastic. The diameter is just about the size of the disk and the thickness of the leather. The middle hole is to push the covered disk free when covered. The white power is simply a mold release agent to help prevent the glue from sticking to the plastic
Disk centered on leather pushed into depression. Fish glue is applied lightly around the rim.
Leather is worked down onto disk, keeping wrinkle free as possible.
Almost completed. Let dry for a minute, then remove by small rod through hole in plastic. The center hold for valve stem will be punched with very small leather punch.
Both sides of typical valves. Any glue on edge usually will pull free with no trouble