Top thickness: Some Rodriguez guitars have only very slight variations from the center of the top to the outside edges. From a sample of a 1976 model, I found that the top was about 2.1 mm thick in the center from the sound hole to a little behind the bridge area, and across the bridge to each edge of the tie block. From the bridge tie block edge across the top (on either side) to the end of the bridge arm, the top then declined on a taper to about 2 mm to the outside edge, and dropped off a little to 1.9 mm on the very edge. My experience tells me that this thickness is fine if a fairly stiff spruce top is used, but a cedar top would be a little too thin for long-term stability.

<<<<New addition: The struts play a serious role in the tone, but most builders are unsure to what extent. The struts are used for stiffeners, but they are important for so much more. After the top is graduated properly, the guitar is strung up to concert pitch, and then the builder will have to go through the sound hole to adjust the struts for the top equilibrium and sound. The far outside bass fan strut and the outside treble fan strut are the balance for the top. The thinner the bass fan is in height, the deeper the tone.   Thinning the outside treble fan will balance the bass.

There is a point of acceptance, so you don't want to go too far with it.  Keep in mind that very little wood has to be removed to get a proper balance. Marcelo Barbero used salt on his finger to do adjustments, but I use a small piece of 150 grit garnet taped to the tip of my finger. Sometimes just one sweep of the finger will bring the tone into balance. You may also want to make some little sanding gigs that will hold to the contour of the struts. You will need a flat stick with sandpaper on it, and also a sand paper stick that is the shape of the strut. All of the sticks should be easy to hold and be accessible to get through the sound hole. There is a way to learn this process, but you have to be willing to destroy a guitar top if necessary. This procedure is not for the faint hearted, because it takes some practice to get it right.

The last bit of adjustment can be done with the sandpaper on the finger tip. Take your prototype guitar and start doing little minor adjustments until you get an idea how the sound moves around. Stay away from the middle strut unless you are doing a flamenco guitar. The flamenco guitar should be designed with even struts that are thicknessed the same. If you are going to taper the top a little on the outside edge of a flamenco, then thin the top of the middle strut just a little to compensate.  Remember, if you get one side of the guitar too unbalanced, then you will have to sand a little on the other side to counterbalance it.