Can’t say that I’ve ever seen SW or ESB on Video 8. ROTJ would have been the most recent release in 1986 when Sony was trying to compete with VHS. CBS/FOX simply may not have bothered with bringing older catalog releases to the format. I think movies came out as long as they did because Sony could afford to keep it afloat.
Curious that http://www.swonvideo.com/ doesn’t seem to have anything on Video 8.