groove 24 the forward surface of the clip member 15 is provided with a cushion pad 29 such as a felt pad or the like for engagement with the rear surface of the coin 12 when inserted also the clip member 15 is preferably prestressed into a generally bow shape as shown in fig1 and 5 so that when it is inserted into a retaining position outer edges of the clip member 15 are retained within the groove 24 and the cushion member 25 is biased against the rearward face of the coin 12 to retain the coin 12 in its seated and retained position this installed position of the clip 15 is shown best in fig5 the clip 15 or other retaining member must have a first portion for engagement with a portion of the groove 24 and a second portion engaging a portion of the rearward surface of the coin 12 alternatively a gasket member such as a rubber 0 ring or similar retaining member or snap ring can be inserted into the groove 24 to retain the coin in a seated position as illustrated in fig6 it is also possible to use both a retaining member such as.