MacOS – restoring to mavericks from yosemite, partition disappeared after fail

I have an mbpro 15" with 2 hard disks:
Main: SSD with OS
Extra: Time machine backups and data

For different reasons I wanted to downgrade to Mavericks. I rebooted with cmd+r and went to time machine backups. Selected from the Extra HD and selected the Main to restore to. Insert Filevault PW, etc, next, etc. I clicked 'restore' and then it gave me an error: "cannot restore" Without any specifics.

Rebooted and tried again but this time I didn't see my Main. I selected the time machine backup, because the Extra hard disk is there. But I couldn't choose Main as a restore point!

I checked with disk utility:

Both HD's are there. But it seems the partition dissapeared on my Main. I can't repartitions or format, the options aren't there.

Verify and repair disk didn't mention anything.

Who can help me restore to Mavericks? If not possible, restoring to yosemite is fine too, as long as I can use my Mac!

This is the output:

**-bash-3.2# diskutil cs list**
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 5B8350BF-20EF-4199-82E6-129EFF19E9EB
    =========================================================
    Name:         Macintosh HD
    Status:       Online
    Size:         255200755712 B (255.2 GB)
    Free Space:   254855766016 B (254.9 GB)
    |
    +-< Physical Volume 907FCDE2-0C62-4951-A39E-36F19244FDB7
        ----------------------------------------------------
        Index:    0
        Disk:     disk0s2
        Status:   Online
        Size:     255200755712 B (255.2 GB)


**-bash-3.2# diskutil list**   
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *256.1 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage                         255.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *1.3 GB     disk1
   1:        Apple_partition_map                         30.7 KB    disk1s1
   2:                  Apple_HFS OS X Base System        1.3 GB     disk1s2
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *750.2 GB   disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS Hitachi                 449.8 GB   disk2s2
   3:                  Apple_HFS time machine            299.9 GB   disk2s3
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *5.2 MB     disk3
/dev/disk4
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk4
/dev/disk5
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk5
/dev/disk6
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk6
/dev/disk7
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk7
/dev/disk8
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk8
/dev/disk9
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *6.3 MB     disk9
/dev/disk10
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *2.1 MB     disk10
/dev/disk11
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *1.0 MB     disk11
/dev/disk12
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk12
/dev/disk13
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *524.3 KB   disk13
/dev/disk14
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *1.0 MB     disk14
/dev/disk15
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                            untitled               *6.3 MB     disk15
-bash-3.2#