Two questions

First: I just received my great grandfather's (William Henry Armstrong) death certificate from Albany. It shows his date of birth as April 19, 1860 in Bayridge, New Jersey. Could this have been a simple error on the part of the family member who gave the info or recorder, or was Bayridge once a part of New Jersey?

Second: Is there any chance of a civil birth record from that time? The death certificate says he was born in 1860, but my grandfathers (Frederick Martin Armstrong)birth certificate says the father (William) was 25 years old in 1884 when Frederick was born. If you factor in the exact dates, his birth year would have been 1858. Or am I going to have to start looking for church records?