Rear quarter lip mods?

On my 72 Swinger the lips were pretty much perpendicular to the fender. To get them started I used a pair of channel locks, there are designated sheet metal crimpers that would work better. Just took little bites on the lip itself all the way around. Tacked a hunk of carpet to a wooden block and took the hammer to it.
THIS, I did the same thing, a pair of 3" wide duck bills, then carefully finished w. a hammer and soft back up on the out side. Would even be better if done in the hot sun,(on the paint). Will end up being a lot stronger when done , than cutting them. Altho I did mine before a repaint, even extended the front to the inside fenderwells.