Looks good MikeB,
I can tell you exactly how that switch needs to be wired, as I just installed one for my strobes on my 3520 cab. The two prongs at the top of the switch require a hot and a ground. The hot will come from jumping your non-constant power on the switch itself. In plain english, the terminal that becomes hot when you turn the switch on. I will not matter which one you put the ground on or the hot on. I have included a very quick sketch. The red will be your constant hot, the yellow will be to whatever you want to power on with the switch. And lastly the black will be ground and the other yellow will jumper to the yellow on the switch. A diode is a good idea, but not a must. Without the diode you will get a glow on the toggle light for a few seconds until it uses the line energy up, then it will go out. I hope that helps.
http://www.freeimagehosting.net/image.php?9cd4b5a115.jpg
Chad
