Whether the aluminum and steel are different in any way (other than the material) I don't know, but Velo Orange uses the same photo for both, so I really doubt the profile is different.
To re-radius the fluted fenders, well, that was pretty easy. Initially I measured them 64 mm outside, 56 mm inside. I cut three pieces of half inch dowel, about 62 mm, 64 mm and 66 mm respectively. I placed the smallest one obliquely between the curled edges of the fender -the 56 mm dimension-- and straightened it, then slid it from one end to the other several times. Then I did the same with the 64 mm dowel, and finally the 66 mm one. The final result is fenders about 72 mm wide and a very nice fit over Rat Trap Pass tires.
So let's see how I'm doing with flickr...
That's one of the pieces of dowel, jammed between the edges. Note how the fender bulges out there. Slide that up and down from one end of the fender to the other, and the whole thing ends up the same width. Then do it with a wider one.
Here's a before and after. One end of the fender was placed at the start of the yard stick; here's where the other end came to rest, before (on the right) and after (on the left).
Here's a before and after of the width. Before is on the left this time. You can see how much wider the thing got.