This I cannot find but it is a minefield of supposition. I find this gem and it is difficult to pin it down.
"I have been forwarded the actual naturalization record for William Arthur on microfiche from the Library of Congress".
This states that the swearing in took place in New York State. This is important because although William Arthur moved first to Fairfield, Vermont, he later moved to New York State. Who the "I" was, I would not care to venture. If it was true, I would wager Chester Arthur would have stated this in the course of conversation. There was discredited investigator, a Mr Hinman. He was hired by enemies of Chester Arthur. Hinman lead off by saying Chester Arthur was born in Ireland. Anything Hinman said after that was likely taken with a pinch of salt.
I can’t find when the information about his fathers’ naturalization occurred was revealed either. My guess is that it wasn’t revealed before Chesters’ winning the vice-presidency or before before becoming president after the assassination. Hinman put everyone on the aspect of where he was born, rather than the dual citizenship, so it doesn’t seem like it was brought up.
Chester said, in the LOC papers, that ‘his father kept his records secret, even from me’, if you can believe that.
That was Donofrio who was forwarded the naturalization record. Here it is if you want to look at it:
http://naturalborncitizen.files.wordpress.com/2008/12/william-arthur-naturalization.pdf