Hi zippy.....
the inner wheel arch is cut away, and a new piece of metale is welded in, the fiberglass rear fenders is from ABARTH pop rivetets on....but i like to get them quickly off, so i have attached them with aeronautics fasteners.....you can use ordinary fasteners....
Inner rear wheelarch is steel.........
Regarding the front wings, a have 1000 of pictures, not 2 is the same, so i improvissed, and welded them on........I hope it is answers to your quistions......
I will use mine for historic race,- and it was homologated with 8 inch rear wheels, so I had to use the TCR rear flares
Kind Regards
Max