Reading Walker & Hall trademark on a fork

I have a set of Walker and Hall forks. They do not have the Lion Passant to denote Silver Content and no Crown for Sheffield. Instead they have the letter H and a picture of a building with 3 crosses on the buildings 3 gables followed by the name HALL then the trademark flag with W&H inside.

Below is a picture of the back of the fork in photo bucket. You may need to copy and paste the link into your address above.
s600.photobucket.com/albums/tt84 … downunder/

Why is there a building on the back of the fork and what does it mean? and was the fork made in Sheffield. Any information about the forks would be greatly appreciated.
Thank you