Is this right?

Hi everyone,

I'm hoping you can give me a hand with a question about sheetmetal. One of the readers of my blog in Spanish asked me how to unfold this part, the one you see in pink in this image.

He actually created a series of surfaces in order to make this and then knitted them all together.  He's using SW 2007, so there's no option to convert the solid to a sheetmetal part. I tried shelling and adding a rip and bends, but I guess I must be doing something wrong, because the rip won't go all the way and the operations fail.

I told the reader to make each triangular section using edge flanges, using his surface model as reference for the right position and angle and modifying the profile of the flanges so they are triangular instead of rectangular. I worked it this way myself and ended up with this. All the edge flanges you see there are the ones I used to make the triangular walls. The part in green is the sheetmetal part and  I tried to "wrap" it around the other shape (the surface in pink) as much as I could. Of course, the original shape has no bends, so the fit isn't perfect, but it's close and the part unfolds. So, I guess my question is: am I right? Is this the way you would do it? How else could it be done? How can the fit be improved?  Remember, he's using SW2007.

I'll attach a copy of the file as I modified it in case you want to see it. Thanks for your help!

SolidworksSheet Metal