First - I am not a D-Link employee - I don't think you'll get much out of them here - back when the forum was started, I believe one of the moderators was an employee, but he's been gone for some time.
Second - if that data is critical - pull the disk and send it to a recovery specialist - the more you fiddle with it, the greater the chance of losing it.
If you are intent on a DIY approach, go to the Acronis website and download a trial version of snap deploy - it's a tool intended to allow you to make disk images for use in a large PC "roll out" where you need hundreds of systems with identical settings, which is not what you're doing - but - it will allow you to make a sector-by-sector image of the disk that you can then do the recovery attempts without fear of damaging the original.
There are tools that can help with the "unformat", but, not being familiar with them, I'll leave it up to those who are to make suggestions.