The middle name and the last name of the supposed source seem to be spelled the same. I wonder if the files of an attorney related to William Blaine were the source of the exhibit, or if we are being lead to that notion?
M Erickson Edit
I was wondering about that too.
Another thing just crossed my mind.
On actual legal documents, sometimes there are anomalies. Spelling, dates, things typed in the wrong spaced, left there or subsequently whited out, etc. Not often, but occasionally. So one anomaly doesn’t necessarily, IMO, give the stamp of “forgery”. The accuracy (as far as what is known) is of equal or more importance, as well as provenance or chain of custody.
I am just a know-nothing, but just from what I’ve seen this can’t be ruled one way or another, although probably fake.
Also, since if this authentic, it would have been filed by the grandmother in a sort of unusual method anyway so that automatically makes it not like most of the other birth certificates.