also depends on what country it was released in, i know france, mexico, and germany had diffrent releases not all of which were from ken films. i've heard the uk also got releases. there are even very rare test 16mm clips made for ken films full frame and 8mm cinemascope versions from ken films, not widely advertised i know i've seen them on ebay.
according to the star wars collectors website there were two versions of empire the one released during the 70mm run and then pulled and one featuring the regular 35mm mix released later. i think ken films went out of business so there was never a digest version of return of the jedi as far as i know in 8mm. there was a film distributor in the uk who had the trilogy in cinemascope full features on like six reels or so. for each. i think the last time i checked they still had return of the jedi if you had like a thousand bucks, lol
the german ones were german dubbed i believe and were cut for censors reasons, i think they were called marketing films and were like short trailers of the features.