Sarah,

Concerning the Nabisco bran cereal that we both are searching for, below is the info I have discovered.

Post, owned by Kraft, bought out Nabisco in the mid 90's. I called Kraft today and they said they have discontinued as of last year, the Post 100% bran, which is the same as Nabisco 100% bran. They could offer no substitute. My muffins just aren't the same--I used it in combination with Kellog's Original All Bran. Everyone loved them. Did your recipe use the two cereals, if so, have you found a substitute?