Most of those old specials and tv shows on Prime look just fine on my 65in and 75in 4K tv's. Sure some of the video quality has degraded, but it looks better than the same shows being broadcast on bitstarved diginets. Some of it has been remastered in HD. I have copies of some of the old Bing Crosy and Andy WIlliams Christmas specials that were cleaned up and remastered in HD for broadcast on INSP, what a difference over the same shows on getTV, but they still looked good and just as enjoyable in SD from the old copies.
Thanks for the reply. What type of TV do you have? My son recently bought a 4K Samsung 43 inch and SD is terrible on it, even streaming. He tried watching the first season of family guy in SD off Hulu, the artifacts were horrible.