Originally Posted by redwhiteandblue

Check that the backlinks actually go to the home page and not subdomains or deep pages that you won't want to rebuild.

I tend to use Majestic on these and if I see a high CF value but low TF it means while it has lots of backlinks, they are mostly worthless or spam. If you check the keyword density and most links have the exact same keyword, it is probably dropped because it was penalised for that.