The idea of getting insurance on the title is a good one in case there is a fight.
Nasty business this. However, did the 2005 lender not find a record of your lien? If county records reflect the facts as you have stated them, you may want to advise the home equity lender of your current ownership to avoid having them show up and try to evict whoever is in there or file forcible detainer after they go through their foreclosure process. Avoiding embarrassment is part of it, but also you want to avoid having to fight them in court (which is expensive) over your ownership. Heading them off by giving them notice seems wise, but your attorney should advise you.