So, lastnight I smeared wallfiller all over 6 of them and let that dry, and this afternoon I sanded them again, not smooth, but leaving a pattern. I used a sponge and added a a grey with a pinkish hue craft paint on all of them, and after that dried a stone grey craft paint, also with a sponge, pushing it into the ridges. Then, using another sponge and a piece of heavy card, I marked all of them with weatherd yellow lines on top. Drilled holes and inserted bent pieces of paperclip and added a wathered down wallfiller to the metal...this creates a beuatiful corroded effect when painted brown and washed. Then some more weathering with a off white sponge for highlights, and right now I'm adding pinwashes with very thinned mud Devlan Mud and Vallejo Dark Grey. This picture is from just before that.
I will do a tutorial on these soon, as they are dirt cheap to make and a ultra fast way to get additional cover on the table.