Hi.
No, unit is still not fixed. Will be very grateful for disk image or any other variant of backup.
Initial boot problem was some damage of Ext3 master block which changed disk geometry.
This resulted in Ext3 journal pieces randomly written to the disk.
I had experience with FAT filesystem recovery procedures so I read manuals on Ext3
structure and spent a lot of time in disk editor finding and linking directories to inodes,
copying sectors, ...
I found deleted SW distribution archive on the second HDD and parts of it copied to СF card.
Was able to recover it from pieces so I had the SW.
Found Bash command history with a lot of commands which were issued on new unit to
install SW for the first time.
Recovered /etc directory and some other directories.
Installed appropriate, clean Redhat version and did my best to apply everything
recovered there.
Now SW starts, sees no keys / serial number, draws main screen with calibration
and then writes "fan error - shutting down".
Fans are OK so SW cannot access the sensors. Suspect that sensors are in UARTs
on the motherboard and keys are also there. So think problem is in accessing UARTs
from the SW. Maybe some settings are missing.