I am a Piper descendant but not from Daniel and Elvira. Daniel's great grandfather Piper was Joseph who md Esther Wright, and I am descended in that line.
I wish I could identify the source of the info I posted for you, but I do not find any notes identifying the source. Most of what I have on the Pipers came from either the State of Vermont records or from two family sources, a typed genealogy manuscript that a cousin produced many years ago and a scrap book of news clippings regarding family members kept by my great grandmother, who was a Piper. I'm afraid that that's all I can offer. Since these individuals are not in my direct line, I suspect that this info came from the Vermont State records, but I'm not sure. I would take the info as a clue to help you in further searching.