Hmmm, to be honest I wish I had the time, and more than that, the courage, to cleanup the code (and this would include major refactoring and redesign). The project is now 15 years old (D'oh!), and was not aimed to live more than six months at that time, leading to an awfully bad overall coding style.
Kinda off-topic, but have you considered translating HTTrack comments and variable names to English ?