I just did it! Here is how it was accomplished:
I created a new type as described within these forums.
I did a screen dump of my pdf file, saved it as a jpg and copied it to the pix/seals folder.
I scanned in my signature and modified it to include a 2 pt. line under it and added the "Instructor:" text below it. I then saved it as a png file within the Signatures folder.
I then modified the new type file's certificate.php by reming out most of the cert_printtext lines except for the student's name, class name, certificate date, credit hours and code.
I set the output to print the "seal" (my pdf's jpg) first, then the signature and all of the rest of the text. I used the location (left from page, down from top, width,height ...) to specify the location of the items to print.
Attached is a shortened version of the type/php file.
I hope this helps anyone/everyone.