Sanborn first creates a Plain Text Matrix of 42X8...

Then he turns Matrix1 90° Clockwise...

To create Matrix2 Sanborn creates 14x24 Matrix2 by writing from left to right from Matrix1.

I have walked through each character to make verify that all are right.

[ENLARGE FOR MORE DETAIL]

Aha! notice the arrow clue to rotate again...so here we go.

Then he turns Matrix2 90° Clockwise...LOOKING FAMILIAR???

Smilie face is a 3!!!! GRAPH #3 Found by José Luis!!!Read Yahoo Message View Screen Shots To create Matrix3 Sanborn creates 31x14 Matrix4 by writing from left to right from Matrix2.

Sanborn seems to create what we call K4 in this step and appends it.... Note now K4 magically appears...

Both Bill Briere and I noted that some of the writing is on the paper, while marker seems to be on the plastic sleeve...

Bill has suggested that #4 Top might be the label for the plastic sleeve and may in some way be used to mark and wipe (palimpsest) certain locations on the slide in matrix... and matrix3 can be slid out and other matries slid in...

This does not rule out that there is possibly another graph labelled "Bottom #4" that could be missing? Layer Two?)

1. It is quite clear here that the "Q" belongs to K3 and the "?" to K4.
2. K3 might serve as a lookup system: This would account for the double Q and ?....Q=>? etc..
3. Possibly another rotation is needed to extroplate K4?