initial data disk is here:
http://www.technics-music-service.de/downloads/index.htm select 7k from drop down list.
The initial disk will have the factory 20 customs in file 1.
Copying any freshly loaded composers to custom will overwrite existing custom styles, you only need the initial disk for those particular styles.
If you want a blank custom, clear an entire composer first then copy the empty composer to a custom slot. Either repeat the copy a number of times, or alternatively save that empty single custom and load it back to the other custom slots you want blank.