The H & N mark appears to be a mark of Hyde & Nevins, which creates a bit of a conflict in dates. The H&N firm was supposed to have been dissolved by 1820, when J.N. Hyde relocated to New Orleans to fully take up his duties in the partnership of Hyde & Goodrich, which had been operating there since 1816.
Perhaps the H&N partnership continued on for a few years without the constant physical presence of Hyde or maybe Gardiner bought out the old stock of H&N. American fiddle pattern spoons that lack shoulders above the bowl, as this example does, tend to be thought of as the earliest version and that would pre-date 1820.
Interesting little mystery.
Regards, Tom
http://www.925-1000.com/americansilver_H2.html.
