Midway through Gently smashed a plaster wall inside the manor and found a cellar. Near the end Gently went around the outside of the building and broke open a door but went down the same set of steps to the cellar.
All through the show there were many views of a very large mansion that was going to be demolished. At the end, the building that was being demolished was a normal size house.
At the start of the series a women in a green coat steps out of a two seater classic jaguar(?). When opening the door a modern car stereo including lcd screen is clearly visible.