Hi capiscuas, I'm happy to see that you are back again working on SubDownloader, actually I had seen on Ohloh that you were commiting again!
Of course I'd like to help you, because I am a HUGE fan of SubDownloader. But unfortunately for now I can't promise my support, as I am quite busy at work, and I can only add small things to osTools from time to time... When SD 2 is out, I'll see if we can add an History tab. I must admit that 2 weeks ago I was looking at SubDownloader's sourcecode to see if I could help you in your effort, but this might be for later...
I am preparing to release ostools 0.4.0 soon, just waiting for a few translations to finish (in particular Slovak and Swedish). I think that this 0.4.0 release will be the stable release for quite a long time, as I (for now) don't plan to add new features (unless anyone should have suggestions of course...).
Anyway, I'll contact you in the future if I can help you with SD.