As an AI language model, I could not find any specific information on "sally-port gallery." However, a sally port is a secure entryway in a fortified building or castle, designed for allowing authorized people to enter or exit without being seen by potential attackers. It typically has two doors that do not open to the same side of the wall, making it difficult for enemies to gain entrance. Therefore, it is possible that a sally-port gallery may refer to a secured art gallery designed with a sally port entrance for safety and security.
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