With regards to Hase Pz IV tracks - ditch them, or use them for sandwich bag ties or something.
I got some AM tracks from Squadron (Czech Master) but these had a lot of flash on them (although they were fairly easy to clean up with a soldering iron) but can be glued together with CA.
After I'd cleaned up the tracks, and compared them to Dragon's excellent tracks, I think I'd have been better off getting a Dragon kit with the flexible tracks, and cannibalising it.
Your other choices are to use Revell Pz IV link and length tracks, but unless you can copy these using RTV etc, it would be a bit of a shame, and there's not much difference in price between Revell and Dragon anyway, and in my view, Dragon parts are nicer.