I will also offer you "props" on breeding such a difficult fish. I'll put it this way, your tank looks excellent, your fish look excellent, and your "hard to breed fish" are spawning! That really says it all! Great job, and if you get the chance write an article about your experience with breeding them, even if you aren't sure what you did right. If you list all your specific water parameters and your maintenance schedule, along with stocking and feeding regimen, that should make a very impressive article to make a sticky possibly with. I know that I would take notes from it.
The truth is that none of us "breed" our fish, but instead we place them in ideal surroundings and they do what comes naturally. So if you can give us what your "natural surroundings" are, then we have a heads-up on what to aim for. Thanks for the awesome pics and your input so far. By the way, I just wanted to say that your picture taking skills seem to be very good as well! Very good shots of your fish!