Unfortunately they only did DSSS for about a year before changing to the newer fhss. All of the old stock or used will have crumbled into dust as the cases were made from really thin cheap plastic. Replacement cases are no longer available.
If you can find cases, I have a couple boards in a drawer.

The DSSS can glitch if there are more than 8 drivers on the stand, especially with the Flysky or newer Sanwa radios around.