Sounds nice, interested to see the pics!
Here's another solution for the 16-35 II, done with the Lee filter adapter ring....
Take an aftermarket lens hood and trim it down to just the bayonet mount then cut out the center threads of the screw in filter adapter ring, and epoxy the two together. Removes all vignetting, sets the filter adapter closer to the lens, and even allows you to use a screw in polarizer simultaneously. The bayonet mount of the lens hood allows for fast attachment and removal of the whole assembly.

