It may be possible to confirm family relationships by comparing test results with Larry or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
AncestryDNA Paternal Lineage (discontinued) 67 markers, haplogroup R1b1b2a1b6b, Ancestry member lwhayer +
Family Tree DNA Y-DNA Test 111 markers, haplogroup R-m269, FTDNA kit #30030
Mitochondrial DNA test-takers in the direct maternal line:
Family Tree DNA mtDNA Test Full Sequence, haplogroup K2, FTDNA kit #30030
It is likely that these autosomal DNA test-takers will share DNA with Larry: