I think it will be hard to find every character in lower case as they simply never used them all I don't think since only mods and stuff had them. Maybe on some more international layouts? I have many other character from Italian, Spanish, Portuguese, German, French, Russian, Nordic... etc... just not have the time to make them all uniform yet. For building it into a font, I think the correct character locations should be followed, I would build it off MS Arial Unicode and put all the glyphs, and modifier shift, pgup etc type stuff in the private use area.