It may be possible to confirm family relationships by comparing test results with Rand 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) 700 markers, haplogroup FT225562, Ancestry member RandallProuse +
Family Tree DNA Y-DNA Test 700 markers, haplogroup FT32969, Ancestry member RandallProuse, FTDNA kit #B35870
It is likely that these autosomal DNA test-takers will share DNA with Rand: