I read about adding signatures, and found that if "fidentify" shows other than "unknown" in the result, that the the file i need to recover may appear as another file extension.
There by, i have an "fidentify" output as --- 612 file type (dont know for sure as i can not access ubuntu), but i think the signature is recognized.
I've tried recovery, but the extension is not available, and it maus be in other format (i hope)

This is a Database file of an invoice software that uses " *.h2.db " extension. Any chance i can successly recover the file?
Testdisk can't recover the partition cause MBR got overritten.
What you think?
Best regards!
Mauro