Here is the heraldry I developed for Free Borough, the free city in the middle of the Fuyondyan plains, for my campaign.
The design is based on my hunch that the city dates back to the days of the Great Kingdom, therefore the blue base. The city symbol is the "standard" aerdy city symbol seen in may other symbols, like the City of Greyhawk, Dyvers Jalpa and others. The crown at the top I imaged to be the old sign for the viceroyalty of Ferrond. The golden dots at the bottom are a symbol for wealth and commerce seen in many other heraldry symbols.