Here are three screenshots of areas I found that had no re-textures.
The characters after the Star Spirit talks to you, Goomba's, have no re-textures.
Do you need the actual files or something?
I attached the entire dump of the area where the Star Spirit talks to you in a .zip
I hope this helps you!
Update: On the first picture, it looks like that "Toad" poster or thing hanging on the right area of the right wall is not re-textured?
Update: Found another character not updated, not sure who it is either.
Two more screenshots added. Its that old Goomba in the door after Goombaria, the one who saved you after Bowser knocked you out cold.
Update: Found another part that was not re-textured, image has been attached. It looks like a side-ways wooden Poke-Ball. (6th picture)
Update: Behind the house of the previous pictures, the old Goomba staring outside is not re-textured, image attached.
Update: Found more un-retextured images, they have to do with the 8th screenshot, you also missed that gate to the right of that old looking Goomba as well

Update: On the 9th screenshot, I cannot tell if the old looking goomba that say's "I just fixed that gate" is re-textured or not, so I took a screenshot, and is the broken gate not re-textured?
Update: It was too quick for me, but, right when you are told to get your FIRST hammer from the old goomba looking out from the Verdana and he is gone, the Verdana is gone too, Mario falls and before Mario falls there is what I think I saw an un-textured image of him. Not sure, but it looks like it.