Recovery from datafiles

Question

Thanks to the recent weather/floods, we lost many of our servers. This included our central database server as well as the server that holds our backups. The database server was running Oracle 12c enterprise on RHEL6. We offload our backups to an offsite facility once a month. Long story short, our most usable backup is over 3 weeks old. The database server was sent to a data recovery place, who managed to get us partial files, some of which we believe contain our datafiles. But these files are incomplete and lack any / all header information. Is there any way of salvaging any data out of these files at all? Opening up the files with a hex editor displays the data we need, but we are taking about a 50 GB database and mining through the datafiles manually would take forever. We have pretty much given up recovering anything but I thought I would just ask the question here in case someone else has had a similar experience. I am aware of Oracle DUL tool (already opened an SR with Oracle in this regard and this was their advice) but the fees they charge are exorbitant. We are small company - we have already paid a tidy sum for the data recovery service. We simply cannot afford to pay what Oracle are asking for, as much as we would like to. Can anyone suggest a possible alternative please? And we are currently reviewing our data backup policies but as I mentioned - we are a small business with limited resources - and we didn't plan for natural disasters like we should have - we are going to be more careful in the future though.

UPDATE : Right turns out the hard drives themselves are fine though the LVMs are corrupt. I managed to rebuild the partitions with the help of testdisk. But I can't seem to mount the drives. I get an error "NTFS Signature Missing". Looking at dmesg it looks like mount has looked for etx3 and ext4 super blocks and didn't find them. So I am assuming the partitions are corrupt.

Thanks in advance.

Alex