Hi DSA, welcome to the forum.
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In appearance, Dutch 17th century silver brandy bowl; lobed oval and on spreading foot, with two scroll handles with dragon heads or sea horses.
My first thought made in Groningen however the year letter is not correct for Groningen.
For more information about Dutch guild marks, including Groningen see:
http://www.925-1000.com/forum/viewtopic.php?f=5&t=32028
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The maker's mark could by
HA conjoined and the 1st (double)mark could be an E(?) or crown(?) with a
X and it could be for Emden (Embda, Emda, Embden) in Germany
http://silberpunze.freehost.ag/index.php?id=30
Emden is a town and seaport in Lower Saxony in the northwest of Germany, on the river Ems. It is the main town of the region of East Frisia
https://en.wikipedia.org/wiki/Emden
In the year 1595 Emden Revolution;
Emden became a "satellite" of the Netherlands and de facto a free imperial city. The city was proud of this status, and henceforth signed all its official publications with S.P.Q.E. ("Senate and People of Emden"), after the Roman model. The city and the Reformed southwestern part of East Frisia built close ties with the Calvinist church in the Netherlands. During the 17th century, Dutch was the language of choice of the leading citizens of Emden.
https://en.wikipedia.org/wiki/Emden_Revolution
I will check it out and let you know.
Best,
Oel.