I cheated

So much for the grafting! Perhaps if it would have worked if the pieces were flat instead of circular. This is what I did instead, a sort of three needle bind off with the right sides together (like sewing a seam, which makes more sense to me). It worked like a charm, the repeats lined up, and most importantly---it fits over my head.

Then Cleo helped me block it: Why must cats always sit on your knitting?