Recovering erased and overwritten data from a cd-rw

I had a CD-RW which I formatted with DirectCD (I'm pretty sure).

Filled up pretty much the whole disc with small backup files over time
(DirectCD remember)

Then thought I no longer needed it, and erased the disc but this time
recording it is as normal data disc with Nero I believe. There is now only
one track on it of course (not DirectCD/UDF)

However this new track only takes up 20mins of the disc so much the DirectCD
data should still be there, after it

I would like some files back from that DirectCD portion, problem is pretty
much all the recovery softwares only scan up to the first track 20mins worth
(because thats just the Nero-written track) and don't dare venture beyond.
Surely some software is able to scan in a raw mode and look for file
signatures etc. Any ideas?