It looks like you are thinking of Stockbridge in Hampshire rather than Stockwell. [1]

Gaius Nipius Ascanius was a prominent Roman businessman and mining contractor whose name is stamped on a famous 75.3 kg Roman lead ingot (or "pig") found in Stockbridge. He was involved with this location because it sat along a major Roman transport and trade route. [1, 2]

The Purpose of the Ingot

The lead ingot was stamped with the name of the reigning Emperor Nero and dated to the second half of AD 60. Ascanius acted as an imperial agent or private lessee managing the lucrative "lead-silver works" (ex argentariis). [1, 2, 3]

Why Stockbridge?

• Transport Logistics: The lead was mined in the Mendip Hills (Somerset). [1, 2]
• The Route: To export the heavy metal across the Roman Empire, it was hauled along the Roman road from the mines toward the Solent coast. [1]
• The River Crossing: Stockbridge was the vital point where this Roman road crossed the River Test. [1]
• The Accident: The heavy ingot was likely lost or dropped in transit at this river crossing, where it sat buried until its rediscovery in 1857. It is now housed in the British Museum. [1, 2]

Later in his career, Ascanius moved his operations north to take up private mining leases in Flintshire, North Wales. [1]

Are you looking into the Roman mining trade in Britain, or would you like to know more about the inscriptions on this specific ingot? [1, 2]