Assembling facts:
Ggggf owned a pub in Mirfield. William Jubb died in 1814.
Brother, Thomas Judd, purchased pub from brother's estate.
Pub called The Flower Pot.
Row of cottages attached to pub building.
Carved, high up on wall was
Symbol W Jubb AD(?) 1812
Unknown writing under name
Stone was at the "back"
Note: What was 1812 referencing - when the structure was built?
Have you tried looking at other nearby "old" buildings to see if there was a "theme" to what was typically inscribed?
Using the map link that Jool provided, around the corner, on Calder Rd, is a building with a white door and above the door is an inscribed stone. However, I can't begin to read the writing on this stone.
I've not yet found another old building with an inscription but I haven't given up looking.
I wonder why the writing would be on the back of the building? Did the river always follow the current "path" or could there have been roads where the river now flows? Why would the name have been on the back of the building? Could the present owners take a photograph for you or tell you what it says? Note: One of my ancestors lived and worked in a pub in Essex in the mid-1800s. I was thrilled to find the pub on the internet and was awe-struck to see the interior. I wrote to the pub, asking a couple of questions and never received a reply.
However, it wouldn't hurt for you to try writing as well?