After 2 weeks of running gddrescue I was able to recover all important files from the disk. Depending on how much data is missing, photorec is probably the best tool to use. If the disk was too damaged to boot its likely not going to be re-mountable. photorec scans the raw image looking for specific file signatures. This process is referred to as “file craving”. Originally developed to recover images from damaged flash media, photorec works prefect for finding Microsoft Office files on a recovered image.
I was also successful in merging two images together. gddrescue allows you to define the start position and attempts to rebuild the whole image. If you start at block 10,000,000 the image will leave “white” space for the first 9,999,999 blocks. This allows you to combine multiple chunks together. In my situation I had an image created with dd_rescue which needs applied to a more complete gddrescue image. All I had to do was point to image and define the start / end position.
