I visited the main walker House in Rotherham,that is now a museum yesterday for a look round,and to look at some cannon records,in the museum itself.
It was closed for the day so I just had a good look at the house itself,which was built with money made made from cannon making.There is a plaque  outside the house, with some of its history,but with no mention whatsoever of the Walkers and Rotherhams connection to cannon making which is barmy.
The former grounds of the house are now Clifton park.

Here is a site looking in more detail at Clifton House