its sheet metal. get a sheet of aluminum, a cardboard box and some sheet metal shears.
make the pattern out of cardboard and fit it and trim it and fold it in half to make sure its symmetrical.
then tape it to the aluminum and trace with a sharpie and cut it out. take a grinder to the rough edges to smooth it out. looks like they took a bead roller to the outside edge to add strength/rigidity.
the bends at the edge look hand bent. you could draw a line where you want the bend, slide the wing into the slots between the boards of a picnic table and hand bend that easily.
hell you could make it out of lexan too and paint it. lexan will bend nicely to whereas acrylic (plexiglass) will crack.
if you did construction paper cutouts in kindergarten, you can make this. just because you arent a juicedz4, laffengas or a newman doesnt mean that you cant try to make things. trying it in the first place is 80% of the problem. skill comes partially naturally and partially with experience… the latter you wont get if you dont try.