It should be at:
http://www.vintagebus.com/wiring/ (has wiring for fuseboxes and whole car) but having a quick look at a couple I'm familiar with, they do look different; maybe they are for USA & Europe particularly.
Don't have a copy of the Australian Scientific Publications/Gregory's Book for Superbugs/1600 beetles but that may be worth finding (the S.P./G. book for beetles up to 1500 has very clear diagrams). Also the small owners booklet that came with the car usually have an accurate pic of the fuse set-up (sorry don't have - someone must have one of those). I find the Bentley manual for Superbug wiring totally confusing.
I like to make my own fusebox connection diagram for each car by making an enlarged copy, removing one fuse at a time, & noting which one works what. This can be very useful. (Keep a clear copy of the final plan in the car so you can work out what's what if you get stuck with bodgy electrics some dark night.)