Crossposting from /r/history, /r/translator and /r/calligraphy, and /r/French - I've deleted my original post, as the language has been determined to be archaic French.
This might be a long shot - but can anyone read this? The only thing I can make out is "May 1692." There's a signature of some kind, but I can't read it.
In the possession of a person in Bridgeville, Pennsylvania, but that's all I have to go on. /r/translators identified it as French, but an old form - and in an unfamiliar calligraphy.
The letter in question -
I can read parts of it, but the resolution is not good enough to make out entire sentences, much less the whole letter. I tried zooming in to about 200%, and that reveals easy words like articles ("cette", "quel", "du", etc.), but other words become too blurry to read. I can tell you that this is not "archaic" French; the syntax and structure of nouns (particularly the use of plural) indicates this is Classical French (or just French). The handwriting is fairly normal given the time period, though it certainly looks like the writer of pages 1 and 2 is not the writer of page 3.
OK, one more go at this - I got the owner to scan the documents at Staples. He found them in an estate sale in Pittsburgh. Here are the scanned pdfs.
/u/JediLibrarian - help!
Additional close-ups - I'm trying to communicate to the holder that they need to be scanned, but this is what I'm working with right now.