I don't think you need to settle for only 5 images in training data. Beyond just the covers (A check of GameFAQs some of the compilations have unique art featuring Wilco), you can actually use the in-game protraits and stills from the series cutscenes (and even Space Quest 5 and 6's in-world stuff if you really need it) if you tag them pixel art. I made a fellow Sierra adventure hero using far worse quality in-game sprites for training data and it works (though she does want a style LoRA more than most characters).