Hi Mike,
Here is a link to the Pelican forum where I found the picture.
Whining of 915 Transmission
Another good source for part numbers etc. and a great "Fiche" is
http://www.***********.com/porsche-parts/911-78-83/porsche_911_parts.php
Type in the Model and then year to see parts diagrams for your car. There are also some very good tutorials on Rebuilding the 915 transmission. Just google them. Good luck!
Carl
PS will try and upload some photos this Sunday.