Ive had a couple of gilt conders, but no longer in my possession. Id keep it in an airtite of some sort - Fire Gilding was still popular at this point which involves depositing the gold on the coin by covering it in amalgam and boiling off the mercury. Certainly of little concern so long after, but Id still be careful.
The arms are mysterious - elephants represent strength (strong enough to carry the city's castle, which likely represents the elephant carrying the whole city), but some historians have tried to link the badge to folklore. Supposedly an elephant defeated a dragon that was bothering its young - perhaps the crest shows the elephant guarding the city.