I remember going to WDW when I was a teenager and seeing the employees with MTX/MTS radios. I believe they were on a 900MHz Motorola trunk system at the time. Several years later, well after they moved to the iden system, there was a guy selling a big pile of their surplus 900MHz equipment at Hamvention. I bought a few MTX9000s and MTX9250s; still have a couple in a tub somewhere, complete with original engraving. Their communications history is definitely interesting.