It seems that the whole ruse of this stamping was covered by a Connecticut courts case of 1872:
https://books.google.com/books?id=pjQsA ... ks&f=falseBoth Atwood and Plume are named. Thanks to the R.E. Davis Boley blog, a catalog is linked where Plume & Atwood show in an add to be still operating sales in 1903 on Murray Street NY with manufacturing facilities still in Hartford, but seem to be out of the silverplate flatwares field engaged in lamps type furnishings at this point.