Not sure how much help but..........

Pam, the only thing I can find about pastry flour is the following, and I'm not sure it is a lot of help. This is from "Secrets of Better Cooking" by Reader's Digest.
"Pastry flours
The best flour for pastry, in general, is all purpose flour, sifted once before measuring. Cake flour is not satisfactory, and instantized flour works well only with specailly adapted recipes. Pastry flour can be used too, but it is not easy to work with and the baked pastry is often brittle. Use it only with recipes that specify it.
Pastry flour is not available everywhere, buat it you can find it, it does make good pastry. This is unbleached flour usually made from soft wheat.
Cake flour is made from soft wheat and is very finely ground and always bleached."

I hope that helps! Becky