There is a Caddo in Wilson Co, TX, but when I looked up John and Jessie on SSDI, last residence was Caddo, Bryan Co, OK.Some of the date information is slightly different then yours.You can obtain a copy of the death certificate for John from the Health Dept in Oklahoma City, OK.It should show the names of his parents.Accuracy will only be as good as the knowledge of the informant, but he filled out the application for his Soc Sec card, and that application should show the names of his parents, his residence at time of application and other data, too.
On the SSDI there a several Proctors with last residence in Bryan Co, OK.J.C. b 1914; Leroy b 1918; Cleo b 1925 (from your list) and a Cecil b 1920, looks like Cecil might fit into this family, too.Who is Elbert Proctor b 1895, is he a brother to John W.?
You might want to check out the Bryan Co, OK GenWeb site, see what they may have online, and be sure to post your query there, too.
J.C. just died in 2001, obituaries often list survivors, maybe any living siblings would be listed?Worth a try.