As for whether it and the Ewoks show are true HD or upscaled… I’ll take your words for it. I think they’re true HD but I’ve been often amazed at how close to true HD the Muppet Show looks and I KNOW that was SD.
The Muppet Show was shot on PAL video, as it was made in the UK, so there’s higher quality there than if it had been shot on NTSC in the U.S.