I have a slight update related to this post, I found a torrent on a Russian site that contained a VHS-rip of "Darkly Dawns the Duck", however the file has both English and Russian audio and I can't seem to figure out how to separate them.
If no one has already ripped the VHS then this might be a good starting point, if anyone's interested PM me and I can find a way to send the file your way!
I also found a copy of Plunder & Lighting uncut as one file, not divided into parts if anyone would like that as well!
Would anyone out there have the original broadcast versions of DuckTales: Treasure of the Golden Suns and/or Rescue Rangers to the Rescue?