As everybody knows, the backup of the K1000 (and K2000 too) consists of two files:
kbox_dbdata.gz which holds the database itself and is simply a zipped dump of the database in one file
kbox_files.tgz which holds all stuff which was uploaded to the box (kbots, MI, Scripts etc) which is a zipped tar-archive, which consists all files unzipped
Both files are needed to restore the box to a older version.
Normally you test the backup to be shure that all is fine.
But what to do, if you have only a corrupted backup?
There are some tools for fixing (if possible) the backup files.
Please be aware: as the backup is corrupted you will never be able to restore all files!
http://filerepair.sourceforge.net/ is freeware, runs for a long time, and is able to repair the tgz, the gz file could be repaired too but I wouldn't bet much money on that.
Got reports http://www.sysinfotools.com/recovery/archive-recovery.html would also help, but never tested it, as it costs money. If the demo is working correctly, may be tested.
http://www.datanumen.com/atr/ will help in full version. In the Demo it only shows if the archive can be repaired.
The best chances you may have if you have a Linux box.
A simple tar xifvz FILE will ignore most errors (usually the EOF error)
Also zcat would work great:
At first you should rename it to .tar.gz
then run zcat kbox_files.tar.gz > kbox.tar If it breaks here, you are _REALLY_ doomed.
untar the kbox.tat using tar xif kbox.tar
If you have results (each way) repack the archive and upload it to the box.
Hopefully you will have most of the files remaining.