I use a bit of 3/8 marine ply, about 150 X 75, with a length of cord attached to one end. The free end of the cord is secured to the left handlebar when the puck is in use. When no longer needed, the cord is used to retrieve the puck and then wound around the ply. It is stored in the left pie warmer, ready for next use.
My current version is not particularly aesthetic, but it works well.
Maybe I will inscribe it with "OzSTOC" using a texta.... or brand it with an iron.... or CNC rout it.... or 3D print it.... or mould using polyurethane (or polyester) resin, or......