Sir or Madame,
Thank you so very much for your lengthy reply it means a lot you've taken the time to go through all of this hassle for a complete stranger and I truly hope that I can pay you back in any way shape or form.
With that said to get to your intial question as far as whom the informant was on John T/F Wilson's death cert that would be his wife at the time Mrs. Launa Jane Wilson but, by this time she was going to Jane. Certificate number 598859. The place and time of death was Menard, Menard county, Texas on 10 December 1930 at about 9 am.
I hope this is enough information. And again thank you and Have a wonderful day.