According the an index entry for his death in Minnesota, Alvah was born 21 Oct 1870 to Charles V. & Elizabeth Elsmore. From other records I believe his father was Charles B Elsmore.
1870 census Washington Co ME for Charles B and Sarah E. Ellsmore
1850 Census Washington Co ME for Charles B Elsimore with his parents (Edward & "Rheuby" Elsimore) and siblings.
Charles B Elsemore died in 1877 and his wife in 1881
also on findagrave.com https://www.findagrave.com/memorial/111018707/_
Census records indicate the Charles B. was born 1832/33, not 1842 as indicated by his tombstone.
Alvah's grandparents were Edward Elsmore born 24 July 1799 and Ruby born abt 1803.
Edward was the son of Moses & Lydia Elsemore.
Ruby's maiden name was Pineo, according to the marriage &/or death records of some of her children.
Moses was born 25 Dec 1760 and died 13 Mar 1842, according to his tombstone. https://www.findagrave.com/memorial/111018204/_
His wife's (Lydia's) maiden name was Andrews.
Thanks for your interest. I have already researched the links you provided, but they provide no direct connection to him with documented sources, etc. He was born after 1870 census and 1880 he was boarded out to another family. I found that. Charles B. is a definite potential family but there are no legit sources so far I have found. And his legal death cert I have lists no parents. So the Charles V. Elisabeth business is just someone playing on Family Search. They provided no sources either which is very frustrating. This year I've also done a detailed frame-by-frame search of East Machias hand written records from that era. Nothing yet has turned up with his birth--so nothing about biological parents either.
I checked Charles B. Elsemore's probate records in hopes that they would name his children. Unfortunately Charles B died without a will and his estate was declared insolvent, when the sale of his assets was not enough to pay all his debts. Therefore, there was no reason to name his heirs, since there was nothing to inherit. You might try to find where church records for the period 1860s - 1880's for East Machias, ME are kept and hope that at the time the family were members of a faith that either kept infant baptismal records or family records.