Thanks in advance for any help with this.
I'd forget about exporting anything from the Under the Sea shower. The "hooks" in that shower are simple planes that would be super easy to create in Blender
Here's what I would do:
1. In Object mode, click on
Add - Mesh - Plane
2. Rotate the plane by clicking r /y/-90.
3. Scale the plane to the size of the existing shower hooks by clicking s and dragging inward with your mouse.
4. Use the positioning arrows to move the new plane until it lines up with the center of first shower hook on the left side of the shower. Make it extend about as far above and below the shower curtain rod as the Under the Sea one does if you want a similar look.
5. Click tab to go into edit mode.
6. With your cursor in the mesh window, click ctrl+3 to go into Left Ortho view.
7. Click U/Project from View to UV map the the plane you created.
8. Click on the Object Data button (looks like an upside down triangle) to open the Texture Panel. Change the UV Map name to uv_0 if that's not it's current name.
9. Tab into Object mode. Right click to select the plane group and shift+right click to also select the the shower curtain group. Then click ctrl+j to join the two groups.
10. Tab back into Edit mode. Move (and resize if needed) the newly mapped plane to an unoccupied part of the diffuse UV map (See pic below for where I put it - there is a TINY bit of unused space on the current map. You could move/resize other bits, but then you'd need to adjust your diffuse texture to fit.)
11. Click 1 to go back to front Ortho view.1
12. Click shift+d to duplicate the plane then esc to select the duplicate. Use the positioning arrows to move the duplicated plane in place of the 2nd shower hook. And so on down the line until you have a plane for each of the existing shower hooks.
13. Select the existing EA shower hook in the UV map and delete it.
Test in game. It looks like this for me:
Now you need to add the circular hook texture with transparency to make it look like the Under the Sea shower hooks.
1. Export the Under the Sea diffuse texture and open it in your image editing program. Copy the hook texture highlighted below:
2. Export the Xtreme Shower diffuse texture from S4S. Paste the copied hook texture from Under the Sea over your new shower hook plane mapped area. Resize to fit if necessary.
3. Add an alpha channel and color it white. Except for the part of the shower hook plane that you don't want seen (the non-shower ring parts). That part of the alpha channel should be black. Play around with your imaging editing program to make it happen.
4. Change the 3rd material in the warehouse (the one with 87/115 for the poly count) from Phong to PhongAlpha.
5. Test it in game.
Hooks are not quite in the perfect place yet, but it looks decent so far:
If you still really want to export the hooks from the Under the Sea Shower, it's possible to do. Just start at Step 8. Easiest way to isolate just the hooks is to select them in edit mode and click "p" to make them a separate group. Then delete all the other groups in the scene window. Export them as a .obj and import them into the new shower. Then pick up with step 8, omitting the steps where you duplicate the plane.