What lines are good for producing good front reach and good angle and lay of the shoulder?

Here is a diagramme of normal forehand construction ie not the exaggerated 45 degree layback required by the standard. http://i58.photobucket.com/albums/g277/carlacot/image001.png

Also note that the FCI standard is incorrect in requiring the shoulder blade and upper arm to be of equal length.  The upper arm is naturally a longer bone by approximately 15%.  They are often percieved to be of equal length because this is the impression given on palpation, but the point of shoulder is comprised soley of the end of the upper arm bone.  The end of the shoulder blade is set back from the joint.

So, in this same context, what is a 'well laid back' shoulder? What angles are we looking at to judge this? The one between the upper arm and the scapula, or the one between the upper and lower arm, or both?

And is 'well laid back' referring to the angle of the shoulder, or its positioning in relation to the ribcage?

Well it depends on who you ask I suppose.  I think most judges look for near 45 degrees as this gives the most forward reach (dependent on rest of construction).  My own opinion is that between 50 and 60 degrees is normal but then I choose to no longer judge the breed.

The shoulder layback angle is measured from the horizontal.  If you see that 90 degree is a vertical line, 45 degree is exactly half way and this is probably the reason why this was the angle perceived to be correct for construction, as it pleased the human eye in its orderliness.

The angle between upper arm and shoulder is measured on the rib side not not in relation to the ribcage.  It's just the angle between the two bones positioned like this   -

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Both angles should be assessed when judging.  A correct upper arm is as important as a correct shoulder.

What landmarks do the judges use for measuring, pod?