Instead of first using the sqb2mtf utility, you might be better restoring all the .sqb files in a single script. To specify multiple files please refer to the section titled "FROM DISK argument" in this document. Don't forget that the script will need to invoke the SQL Backup extended stored procedure (as shown in the Examples is this document).
https://documentation.red-gate.com/display/SBU7/The+RESTORE+command
https://documentation.red-gate.com/display/SBU7/The+RESTORE+command