Recently I read a posting on one of the other pen boards discussing the now very hard to find Sheaffer Skrip Persian Rose Inks. Al Besser, if my memory serves me right came up with a recipe for a substitute so since I was going to order somne ink anyway, I deceided to give his recipe a try.
The recipe calls for two parts J. Herbin Poussiere de Lune to one part Pelikan Violet. My inks arrived yesterday, so first thing this morning, I mixed up a batch. I inked two identical Esterbrook J's that I just put new sacs in a few days ago, one with the real McCoy, Sheaffer Persian Rose and the second with the new Herbin/Pelikan mix.
The result - almost identical and unless you view both side to side under very bright 5000 degrees Kelvin light, the differences are imperceptible.