I saw this on the HAMB hot rod forums done in 1:1 and was kinda keen to try it in scale. I also thought it might be a good tutorial if it came out well so I took several pics to share. Hope you like it.
Step one. Find two pick-up step side fenders. In this case '55 Chevrolet. Glue together with your favorite "this ain't never coming apart" medium.
Clean up the seams. Less work to do after you have it all cut apart.
As you can see there are two possibilities now. An angled piece created from the rear of the fenders and a flat section from the front. For the purposes of this tutorial, I decided to do the flat section. The rear piece I may do for a future project.
I reinforced the inside of the shell with some half round stock.
Draw out your cut line and break out the zona saw.