Also, if you can make a second diagram that listed the primary pin designations and has a empty box so that the user can designate what pens are used for what purpose in their project, it would be very helpful.
Seems that you had a similar need, that I had. I created a diagram for the DigiX, where I combined both needs in one document.
There is an empty transparent form field over the additional information, which can be filled. Once filled, the field chances to solid background and covers the initial information.
Have a look at:http://digistump.com/board/index.php/topic,1211.0.html
When Graynomad allows, I could overlay his PDF in the same way!