I've gone through the five stages of grief with this ink (Sailor Bungbox Kabayaki of the Hamaneko Eel) which cannot be had for love or money unless their ink-sensei decides to make more. The sixth stage, of course, is making a substitute. 2/3 Iroshizuku Yama-Guri, 1/4 Diamine Oxblood and a bit of Diamine Ancient Copper for the bit of yellow. It's simpler, but close enough for rock 'n' roll.