USA, trade dollar 1877 San Francisco

Very nice piece with impeccable details and pleasing to the eye patina.

A typologically rarer item on the Polish market.

Obverse: Liberty seated to the left, below her the date 1877, surrounded by stars;

Reverse: eagle of the States, above it a ribbon with the motto E PLURIBUS UNUM, below the eagle 420 GRAINS. 900 FINE. and mint mark S, in the rim legend:
UNITED STATES OF AMERICA TRADE DOLLAR;