[itsme]

My tablet with android 4.4.2 is back and after several backup and restore cycles I came to these settings and storage locations:
Let MobileSheets Manage My Files: OFF
Set the MobileSheets Storage Location: external SD card
/storage/sdcard1/Android/data/com.zubersoft.mobilesheetspro/files
Expose Database File: ON
The "one file per song" part of my library is stored in internal memory 
/storage/emulated/0/_MobileSheets with subfolders /A ... /Z. 
This is required because I have a number of ChordPro files and want to be able to edit them directly on the tablet. If they are on the external SD card, my editor cannot write them.
The fakebooks are in 
/storage/sdcard1/Android/data/com.zubersoft.mobilesheetspro/files/Fakebooks
I was surprised that
/storage/sdcard1/Android/data/com.zubersoft.mobilesheetspro/Fakebooks
(without /files) did not work. If I stored the fakebook files there, they were restored to
/storage/sdcard1/Android/data/com.zubersoft.mobilesheetspro/files
as reported in my first post.
Surprisingly because MSP should have write access there,
/storage/sdcard1/Android/data/com.zubersoft.mobilesheetspro/BAK
can be used without problems to write backup files.