Any ideas for a password? Numbers, letters, length, encoding, etc? If you are sure that it's on the disk and there is some idea of ​​it's format, then you can find everything that looks like a password scanning the dump of the disk or using direct access and try to use it to unlock the wallet in auto mode. But programming skills and knowledge of files system are needed here. For example, there are MFT (master file table) in NTFS. And small files (called resident files) are store entirely within their MFT record. I think recovery program should do correct restore this files, but if MFT damaged maybe better try to restore manually. So first step for NTFS is scan MFT file for small txt data.

You can try to restore the partition using different programs.
For low-level access, manual recovery, dump I used WinHEX (but you need to figure out how the file system works), to restore partitions - testdisk.
For automatic file recovery, it is better to try as many programs as possible, sometimes different programs sometimes give different results.
In any case, first of all you need to have a copy of the disc in case the original accidentally damage.
Good luck.