cut your mesh in QUADS
UNWRAP again
add the solidify modifier, and apply
after this do the following
- Save you Blend
- CTRL + A
- Apply SCALE and ROTATION
to return the value of the scale to one
- save your blend again to update all
separate PIECES !!
see the screencast key in the gif
Step 1
Step 2
Step 3
separate the pieces one by one until completing this
NOTE: it is very likely that you have to adjust your uv map of each of the pieces because you have separated them and you have added new faces, you can use the same texture just place the uv in the place where the part that should texture your texture is, worth phrase redundancy
Remember remove dobles before you separate the piece
Step 4
repeat the process in each piece until you complete everything
another way to separate the pieces
obtain this