[link|http://www.hallogram.com/valkyrie/|Valkyrie] - a Clipper decompiler. I don't know how well it works with protected code (if that's an issue) and it doesn't work with 5.3. That may not help you if the libraries in question aren't written in Clipper.
You're probably aware of tools like that, but just in case you weren't...
Luck!
Cheers,
Scott.