I've just used the GALtools decompiler with a RM.1 logic extracted from the Apple II version of KQ1 and I can confirm that it decompiled it without issue. There were a few differences in the logic of the script, and the word numbers have been rearranged a bit, but in general it was the same script, and the format was the same as supported by the GAL decompiler.
I find this interesting because Jeff Stephenson was the one that ported KQ1 to the Apple II. The data in the main part I would guess is very similar to the PCJR version of the KQ1 game, so Jeff would have simply been porting the interpreter to the Apple II. What I find interesting is that I'm currently imagining that Jeff was the one that brought about the rather dramatic changes to the interpreter that were introduced with King's Quest 2. NewRisingSun is quite right in that the original KQ1 interpreter is quite different from all other versions of the AGI interpreter that followed. I think we've already established that the interpreter was known as GAL or Game Adaptation Language prior to the release of King's Quest 2, so it seems reasonable that we call the KQ1 interpreter GAL, not only because we know it was called that, but also because of how different it is from the other AGI games. King's Quest 2 and all AGI games that followed were quite comparable to each other (ignoring the fact that in AGIv1 games, vars and flags were the same thing). - Jeff claims that he wasn't involved in writing the original interpreter used with KQ1, so in my mind I'm imagining Jeff porting it to the Apple II and thinking of all these ways in which he could improve the interpreter, and perhaps that was what we saw with KQ2, i.e. the incorporation of his improvements.