The TAR files were created by concatenating the data sections of an 8" floppy disk backup set. 

Cdc114dg.imd "Diagnostics for CDC-114 20M":
This disk was archived using a Kryoflux, decoded with the PCE tools, and converted to IMD.
This disk image uses 128 byte HD MFM sectors, which requires a special floppy controller to write.

x22root.imd "Xenix 2.2b Root - for CDC-114 Altos 8600"
This disk was archived using a Kryoflux, decoded with the PCE tools, and converted to IMD.
This disk image uses 128 byte HD MFM sectors, which requires a special floppy controller to write.

Xenix full dump (7-10-1984).tar:
This appears to be a full backup of a CDC-114/Altos 8600 system.
There were a few bad sectors on disk 4 of the backup set, so a few files will be corrupt.
According to the label, archiving at disk 6 was "restarted" for some reason. 
There are also some file names that can not be extracted on a Windows system. 

Damaged files appear to include:
/bbqa/cdbc/io2.bb
/bbqa/cdbc/pf1.bb
/bbqa/src/kadd3.bb
/bbqa/src/lkadd2.bb
These are all business basic source code text files. 

spar (5-7-86).tar
This appears to be an archive of a "sparse file archiver"
This was read with no errors.

Xenix 2.2b - Runtime Utils.tar
This is an archive of Xenix binary tools for Xenix 2.2b. 
This was read with no errors.

Xenix 2.2b Dev Utils.tar
This is an archive of Xenix binary development tools for Xenix 2.2b.
This was read with no errors.