It may be possible to confirm family relationships by comparing test results with Cecil or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Family Tree DNA Y-DNA Test 111 markers, haplogroup R-M269, FTDNA kit #113855
It is likely that these autosomal DNA test-takers will share some percentage of DNA with Cecil:
AncestryDNA, GEDmatch T761801[compare], yourDNAportal CEC8caee44b, Ancestry member Trele6
Family Tree DNA Family Finder, GEDmatch T761801[compare], yourDNAportal CEC8caee44b, FTDNA kit #113855