Jerry
Its called a "tray case" in which the top pieces latches to the bottom and the bottom stays put. I had one custom made for my Yamaha EMX 512 mixer and I now see there being mass produced and available on Ebay. I contacted one of the case companies who advertises on Ebay about making one for my keyboard and they said no problem, only the bottom piece would have a 1.5" lip so you have to know if that will interfere with any plugs or whatever connected to the keyboard.
Let us know how you make out