I am excited to hear that a DNA study is being done! I'd be interested to hear more about it, who is doing it, etc.
The letter you mention was actually dictated by Edward to his granddaughter, Dorris Estelle Maxwell in 1931, rather than by Bazel to Edward. (I sure wish Bazel had dictated one--it would be most helpful.) Edward was an older brother of my great grandmother, Nancy. I'd be happy to send a copy if you like. Just send an address to post it to.
Which branch do you come from in the family tree? If the cousin you mention that is a direct descendant of Edward wouldn't mind your passing along his/her contact information, I'd be very grateful.