Had to tweak the alpha of rome struct a bit.
1. Open broken texture in blender
2. Export it from blender to jpg to get the alpha details back
3. Import it in Gimp, load the broken texture.
4. Use the alphaMap of the broken texture as selection
5. Color to Alpha, on the jpg one, (Don't forget to add alpha channel)
6. Add a white 2% transparency layer below everything
7. Hide all the layers except the jpg one and the white one
8. Export to png
9. Done !