It's not that hard to convert a letterboxed video file to "anamorphic" (that's what all the "anamorphic" LD rips do). But the purpose of real anamorphic transfers is to gain vertical resolution. Stretching a letterboxed transfer vertically doesn't add resolution. Can it be done without re-encoding and losing quality? No. But it might be possible to make a faux-anamorphic (or "fanamorphic"[TM]) version that looks better than watching the official disc with on-the-fly scaling. The best way to do this would be using the PAL DVD as the starting point for the video, as it will have more lines of vertical resolution to begin with. However, for anyone with a 4:3 TV this would be pointless.