William Dupree is noted as being an existing New York Silverplater at the time he partnered with E. G. Webster to form Webster & Dupree in 1864. (He later became factory superintendent in Brooklyn with Webster heading the firm.) However, I find no known marks for Messr. Dupree from this earlier era. Here is a Wm. Dupree marked fork of unknown origin in a Tipt pattern with engraved initials, both topside. Is this our plater or maybe a coin product? TIA & Happy New Year!!
Here is an additional fork, flatter but both thick and yet malleable, found in the company of the Dupree sample. It has no maker mark, but the initials also end in a "G" so it might have origins with a single family. In addition, closeby was found a third item with initials "HIG", being a much later sterling dresser mirror from Saart Brothers. All coincidental but suggestive of one line of heirs being the source.
I vote for before Dupree's Webster period and silverplate. The second Fork makes me think coin. Wm Dupree was born in England in about 1816 and died in Brooklyn in 1891. The only listings I find for Wm Dupree concern silver plating. Happy New year!