I have a Tradition 42R with that diagram. It looks like it doesn't apply, but look more closely. Ignore the letters at the top of each column. Start from the right, there are six columns of fuses. Then relays, then the 50's. To verify, pull one that you can identify and test.
Under the top step are the Spartan chassis fuses. There is no diagram. Use a flashlight to read the legend printed on the fuse block. Pull the relays to read what is under them.
'05 American Tradition 42R