'Market Green' cabbage

This is such a beautiful head of cabbage, I had to move it from the garden onto the windowsill, where it will look gorgeous for a long time before I decide to eat it. I know its name, 'Market Green,' because John made a label for it when we started the seeds, and the label moved with the plants into the garden, but, for the life of me, I can't find the seed source (even though I thought I'd saved a copy of all my seed orders). Hope the source will turn up, because I love this beautiful, blue-green cabbage and want to grow it again next year. That's a vase full of Austrian winter pea flowers next to the cabbage.