trouble decoding / mounting

Hi andlabs, love your app!

I am however having a little trouble decrypting a 1TB symwave encrypted drive. Here's what I've done so far:
- created ddrescue image of drive (had 1 read error)
- used reallymine to retrieve the DEK - looked ok
- used reallymine to decrypt image to a new image file
The image looks like garbage and no commands will recognise any partitions on it.

I followed a PDF by @themaddoctor on how to mount the drive directly and got the same DEK so that seems solid. Trying to mount the ddrescue image using cryptsetup though still had it appearing with no partitions.

Not sure if there's something I'm missing when dealing with an image file rather than a drive but hoped someone could lend some advice?