I used the same paint on my derby cover on an FXD. After roughing the metal up with some sandpaper, I intentionally sprayed on a base coat followed by a single, ridiculously heavy coat to achieve a flaky, wrinkled appearance. I put a few lighter coats on afterward to fill in the gaps/recesses or whatever you want to call them (basically so the flakes wouldn't flake off). Has held up almost perfectly 7,000 miles later despite frequent kicking and scuffing from my boot when going for the jiffy stand. I can take some pictures and post them if anyone's actually interested.
I am def. into trying this, but could use some info on how to prep them first... I have chrome, stock pipes on my 2006 FXD and would love to just black them out...
Thanks!