Today I was, mostly unsuccessfully, looking to see what Casio has to offer in the way of EWI instruments and I came across this site
"We Fix, Repair, or Buy any Casio DH-100, DH-200 MIDI Horn or Accessories
If you are looking to purchase a quality used Casio DH-100 or DH-200 MIDI Digital Horn or have one that needs to be repaired- you have come to the right place! We are your Casio Digital Horn Headquarters! We also sell DH Series mouthpieces, neck straps, manuals, carrying bags, AC adaptors, and other accessories."
Their Wind Control forum has been abandoned too. But they have updated information at the Wind Controller FAQ.