Here is a photo of one of the fenders I modified. I didn't care for the way the DuraFlex one looked and alo the fact that you needed to modify the battery tray and also the washer bottle in order to get the fenders to fit. I looked at Norms fenders and the one fender has to small of a vent and the "hood scoops" on the other fender are not all that attractive. So I decided to make a fender that can bolt on with only modification to the fender support needing to be done. Blue is not the color of my car, I just shot the thing with some paint I had kicking around to see what it would look like. I still have to do some more clean up on them and have them painted by an auto body shop which will get done when the rest of the car is finished.
Thay are coming out pretty good. Because I had to cut the cross brace on the fender support I added a 1"x1"x1/8" aluminum L channel to the back side of the fender long the edge where the wheelhouse liner screws to the fender. I kerf cut the L Channel so it follows the shape of the fender. I have it fiberglassed to the fender and the bolt that goes through the bottom of the fender to the support attached to the frame also goes through the L channel. I added a piece of 1"x1/8" aluminum flat bar and fiberglassed it to the backs of the vents and also to the fender at the bottom. I bolted the bar to the fender support at the top.
The fenders are solid, My concern was with the bump stops for the hood being on the fender and the hood impacting the fender and causing it to flex because of the removal of the cross brace. I am pretty sure that with the addition of the support I will not end up with cracked paint on the thing if the hood impacts the bump stops.
I can shoot some photos of them primered and on the car if you like. The problem is without a hood and bumper on the car it is going to be hard to judge how it is going to really look. I think that with the harder lines on the RK sport bumper cover it is going to be a nice way to make the transition from the bumper to the curvy door and back end of the car. The other thing is the size of the vents are large it is 3" wide at the top and tapers down to 1" wide at the bottom and each vent is 4.5" tall. I also set the bents back from the wheel opening about 3 1/2" This will provide enough room between the wheel well liner and the vent to get plunty of movement of air. It also places the vents right at the spot on the fender where it starts to flare out. So the plane of the vents maintains the same plane that the back portion of the fender is on until I get past any obstructions and then the vents curve into the car to make the vent openings much larger.

Here is an image where you can see the size of the vent openings and also how the ventys curve in to make the larger openings. You can also see the L channel I added. the L channel is 3 1/2 inches away from the vent openings so it does not hinder air movement into the vent nor will it be able to be seen.

I am interested in hearing peoples thoughts on them.
Note: I did make the fenders in my house fiberglass, bondo and painted them. I have 3 charcoal air filters that are 5' tall and 1 1/2 foot in diameter each fitted with a 10" 1000 CFM fan and also a muffler. You would never know I was doing that kind of work in my house.