The steps were unearthed during the recent Liverpool One excavations. This was Liverpool's fourth Custom House, completed in 1722, and stood at the east end of the Old Dock. This served before John Foster's fifth Custom House, which was built (construction started) in 1828.
In the book "Liverpool Slavery" published in 1884 by "a genuine Dicky Sam" it says that '[T]he Custom House... was a meagre looking building on the East side of the Old Dock, with a flight of steps leading to the main entrance, and on these steps the slave auction was held'
A point to add, as many of you will already know, slave auctions didn't actually take place in Liverpool, these were were held in the Caribbean and the Americas after the dreaded Middle Passage. However, auctions of "so called" captain's privilege slaves did take place in the local Coffee Houses and, as the Liverpool Mercury reports, in the warehouses by the Salthouse Dock gates. So there may be some truth to the claim.
The stonework and steps themselves were made from yellow sandstone, the same stone that capped off the top of the Old Dock walls. It may have been salvaged from Liverpool Castle which was quarried in part when building the Old Dock.
The Custom House steps, excavated.
The Custom House at the east end of the Old Dock
The Custom House
The Custom House behind the Old Dock
George Perry's map, 1769