The source is
Kobayan, a pretty well known site dedicated to the arcade scene.
After reading your article (and agreeing on everything you mention about the sources, as you'll know), I'd suggest you to remove the Milestone naming thing from it. Milestone does very well know what they're doing.
Japanese love to play with naming ambiguity, you know. Rajirugi's actual romanji form is "Radirgy", not just because it comes from "radio" + "alergy", but because THEY wanted it to be so. It's up to them since the Japanese language allows that. It doesn't matter if they use the strict romanization "rajirugi" for its website's URL or whatever. That's just a direct transliteration, useful for that stuff. The same goes with "Karous". That's its official form. It's, most likely, a proper name Milestone has invented. With the kana, they just tell you how to pronounce it. In this case, it plays with the Japanese name for "crow", additionally.