Unless anyone with a 45CF responds in the meantime, can you post some images of the flange back scale to let us see what you mean?

In theory (and there are many people on this forum who can advise) the distance from the GG screen to the lens nodal point should be the same as the focal length of the lens in use.

So if you had a 150mm lens, then the distance from the gg screen to the lens panel (approximately) would be 150mm. Likewise a 90mm lens would have the panel 90mm away from the screen.

Another method would be to mount the lens, focus on infinity and mark the focus guide for that lens, then do the same for other lenses.

The "free guide" I suspect may be to help with DOF calculations, ie mark nearest focus, mark furthest focus, then using the formula work out the aperture to give you sufficient DOF.

Mike