WSSyxSplit

If WS Syx Type reports that the sysex file you dropped onto it is of the type "Multiple Sysex dumps in single file", you can use the tool WS Syx Split to break up that file into individual sysex files that will be compatible with the Legacy Wavestation.

You simply start up the application and drop the sysex file onto it from the Explorer/Finder and it will create some new sysex files whose name is based on the original file name, but with the type of the contained data and the bank number appended. If you want to "bulk process" a load of sysex files in one go, simply select multiple files in the Explorer/Finder and drop them onto WS Syx Split.