I found information on your Ancestor, Archibald Armstrong.
He did marry Anna Elisabeth Krems, the widow of Maj. John J. Eisenlord. They were married 11 Mar 1784 in German Flats, NY. They had one child together, Gertrude Armstrong, who was born 20 Jul 1788. (Gertrude maried John Philip Nellis on 27 Nov 1808 in Stone Arabia, Montgomery, NY.) Archibald Armstrong died in 1792, to my knowledge, and was buried in Rome, Oneida, NY (apparently where his first wife, Elizabeth Stahring, was buried. I found alot of this information, I recollect, in the "Early Families of Herkimer County, NY.", which you might find on line with Google books.