Forgive me if I suggest things you've already tried. Have you checked for probate and land records in Hunt Co, TX? If you look for land records, be sure to look at index long after he died. If the land is sold to another family member, they often didn't pay to have it recorded, until they finally sell it. Then it has to be brought up to date for clear title to new buyer. If you cannot go to Hunt Co, TX, see what has been filmed by the Family History Library, using the online catalog. You can order the film out to your local Family History Center, for a nominal fee, and have about 3 weeks to look at it when it does arrive.
Also, tax records - you can obtain microfilmed copies of tax record for TX counties on interlibrary loan through your local public library. If Edward is on there and then disappears one year, but his wife's name appears the next year -- he is dead.