I've posted Appendix A from R.P. Mitchell's 1960 dissertation, The Society of the Muslim Brothers.
Mitchell expanded and republished his dissertation material as a book in 1968, still considered essential reading in the field. However, the dissertation's appendices of 50s-era Muslim Brotherhood (MB) letters and publications were not reprinted in the book. As far as I can tell, they're no where to be found on the Internet. And so I'm making them available through my blog.
The documents are in Arabic. I can't tell whether there's anything earth-shattering in their contents. I doubt it. They are more likely to be historical curiosities to MB scholars and, quite frankly, MB members. However, I believe it's essential that as much primary source material be made available to the most number of people. It helps generate new insights and new ideas, and I hope, that it will become the raw material for our future response to radical Islam.