I have an Iowa ALLEN family.My great grandmother's name was Bertha Eliza ALLEN McDorman (b 3/13/1869 IA d. 10/4/1958 CA)parents were William and Eliza ALLEN--they lived in Belle Plaine, Iowa in 1890.
Perhaps your Frank ALLEN was an uncle or brother. I know she had a sister Jennie and a brother Linc (wife was Jennie)all born in 1860/70.
Is your date for Eli ALLEN ?1860--Frank was born 1866
I feel her parents were probably born in the 1830s.Her immediate family was 6 or 7 children and Father William was supposedly from a large family.I have had a hard time with Iowa follow up. However, Grinnel is not too far from the Tama, Benton, and Marshall counties.
I also know that there was a large concentration of Allens in the Luzerne area.