Bryan, flipping the tail light over won't quite cover the indent in the fender, close if you position it a little higher than where it was. You also end up drilling three new holes in the fender as well. The pics that Ed are talking about, if memory serves had the tail light moved up to where the license plate is(was) and the plate repositioned so that the tail light now shines down on it, make sense?
I had to replace my rear fender due to an accident and tried playing around with a few different light ideas but the indent kept me from doing much..... Sooooo, I just cut the thing out, welded in a new piece so it would be smooth from top to bottom and put my tail light of choice on. Got one of the LED '39 Ford style tail lights from the Shiney Hiney folks... me likes.