Recuva found everything on that drive less those specific music types. The drive in question was just about full at the time the drive failed, and the total filesize that Recuva claims to see after a fully indepth analysis does not add the OFR and LA files.
Additionally, a few of these files were still visible as normal on the drive. (Meaning Windows Explorer still had the ability to browse these as normal..) The "fully indepth analysis" I mentioned just above included ticking the "Scan for non-deleted files" option. After the lengthy scan (put it on prior to bed and checked it in the morning) I saw that Recuva didn't even detect these. I picked five random songs of OFR/LA type and copied them to my desktop and had these codecs decompress the random songs and reports were fine. Additionally, the songs PLAYED fine, so there wasn't any physical corruption. (LA type in particular will crash winamp if the file is not 100% perfect... -.- )
I cannot say for certain just HOW to go about searching for files on a HDD without refering to the drive's TOC, but I do theorize that the program in question has to be able to recognize a certain file-type's header to pick it up. These are admittedly obscure formats so there is no reason to think that Recuva has these formats naturally, thus the request. Or am I way off base here?
Thank you in advance for a job well done.
Edit: edited slightly for clarity.