A 19th Century gold rectangular brooch of ballooning interest

A 19th Century gold rectangular brooch of ballooning interest, centred with an engraved balloon with two flags and set with a pear shaped and circular cut diamond. The balloon floats above an engraved seascape with two yachts, a building to the left and coconut trees to the right. The reverse engraved 'Marco 28 1897' Marco is Portuguese for March and consequently the scene could be to commemorate a ballooning incident from a Portuguese colony, possibly South America. 4.7cm wide.