Navistar, that's pretty nutty, but I can't say I haven't paid through the nose for something I really wanted on eBay before (I'm glad I have retired from gas mask collecting). Anyway, be careful when you mod them. And since money is no object, buy yourself a Dremel if you don't already have one.
Here is a link to how I did it:
http://www.nofuture.com/myvx/mods/roofrack.htm
You can quite easily make a mess of your rail covers if you are not careful. My instructions take you as far as the first "test fit". What I found after I cut them is that the back side of the rail covers were under significant pressure. In the end I notched out another little section on the back. Also, the nice matching gray color is only skin deep. As soon as you cut into them you will expose the light biege color, which you can paint like I did. Anyway, good luck and let me know if you have trouble. Make sure to use a Dremel, I don't know how else you could do it.
Bart