The saving throws will be divided by 10-foot by 10-foot sections. That will be six different saving throws.
The bottom ten feet of the floor & walls -- east and west. The middle ten feet of walls on the western and eastern walls. And, the top ten feet of the ceiling and walls -- again, east and west.
The saves for the western walls and floor/ceiling sections will be at -4 to save vs. Vinny's spell. The saves for the eastern walls and floor/ceiling sections won't have any penalties. The normal saving throw bonus is +17. The weakened areas save at +13.
Stone Shape is a 4th-level wizard spell, and Vinny's caster level is 7th level. The save DC is 18. Rolls in next post.
This assumes Vinny places the spell within the weakened area, which is a given at this point. I just need to know exactly where, so if the rolls fail, I can put it on the map.