Delta Co, TX GenWeb site has link to probates for several counties and probate for A.F. Anderson in Delta Co, TX, was recorded 14 Oct 1887.I think I would send for that record.See who is listed as heirs.
Then post on that site -- the Delta Co, TX GenForum site -- and the Record Lookups site here on the Forum.See if anyone will look for an obituary for him.Or, any other records pertaining to his death and probate.Sometimes probate records will give actual date of death. Volunteers listed on the GenWeb site do not include anyone who does obits, nor is there anyone listed for Delta Co, TX on the RAOGK site.Most deaths were not recorded prior to 1903 in TX.
If you haven't used the Record Lookups, go up and click on My GenForum, click on General Genealogy and click on Record Lookups.
I notice you responded to an old post from a lady who, at that time, worked in the Delta County Clerk's Office.She hasn't posted anything since 2001, but I would try emailingher direct, see if it bounces back.Maybe she no longer works in that office, but might know someone who does.