Yeah, after looking at many ebay stores and webpages in general, I've come to the conclusion that they do not sell black blank keycaps, although they have to make them for the models you've mentioned. What I don't know is why they sell blue navy blank but not black. Another option I have for the Leopold FC900M is to leave del, ins (which, after all, are not useless in that position) and then change pgup and pgdn with printscreen and pause. For that I'd need some black front printed keycaps with these legends. I've e-mailed Leopold directly with the hope (very remote) that they send me some of these keys.
