I've read the original Del Rey releases years ago, they included pages of translator's notes which is very useful for a satire manga like this, I think some translated interviews with Kumeta and his editor, and even SZS reader fanart from the magazine it was published in.
You'll have to compare these scans with the official release to see if they're worth replacing, but Del Rey is long defunct, so I believe it's fair game to upload the first eight volumes hereCorrection: I think Kondansha got the rights to republish those old translations. There were only five more English volumes officially released after that, but they were by Kondansha USA.