Hi Kay
Welcome to the forum, sorry but I can't help with a photo of Old Moat Buildings, but I'll have a look around and see what I can come up with.
In answer to the question from back in 2011, The Great Stone like most of these types of rocks was a glacial boulder deposited by a glacier back in pre history. So it was probably in the locality when the Inn was built and the stone was utilised as a mounting block by horse riders.