I can't help with Ben's parents, but maybe something withinmight be of help.
1860 Wood Co WV Household Gender Age Birthplace Benjn Alman M 80 Delaware !! Mary Alman F 66 Pennsylvania Mary Spoon F 13 Virginia
Ebenezer United Methodist Cem, Marshall Co WV ALLMAN, Mary w/o Benjamin 11-24-1868 ae 75
I didn't find Benj's death record/cemetery
Marshall Co formed 1835 from Ohio Co Benj was in Ohio Co by 1820; also here 1830
1830 Ohio Co Benj ALLMAN 2210001-11001 [print blank census forms for each census yr, so you can decipher/record the info]
I believe this may be your Benj 1810 Fayette Co PA...he and wife have 1son/1dau under 10.
Also think John AL[L]MAN b 1813 PA, 1850 Ohio Co [W]VA is Benj's son.Also Elisha
The children????Not sure, just a theory. son bef 1810; d young? dau bef 1810 John 1813 dau? 1815ish Joshua 1820 Elisha 1820 Dorcus 1820 [all 3 b aft 1820 as not listed 1820 census] Geo. Wash. 1823 Frederick 1827 Abraham 1828 Benj 1832 Mary 1833