The upper part ID is 0003CDE6. The lower part ID is 000b9BAE. As a side note, while searching for this I found a raiseable human skeleton in the pond to the right of the entrance of dragonsreach (a good pet for necromancers

).
The place VirusType2 is descriving is the part of the floor when your enter the shop. The ID is 0005D181 . Nothing to do with the counter. If you disable the counter you'll see that the seam is witht the rest of the floor, both in the point where the counter beggins and at the opposite side. Interestingly, if you delete that chunk of the floor, you will find two chests there. One is a pickable object with the suggestive "do not delete" name and the other one seems to be the vendor inventory. I Suppose in this case the perfect solution could be to add a black 'sheet' under the planks.
Those two chests are below the floor of all shops. This is interesting
