Oh, I don't know how much grams, they sell it by its thickness here :rolleyes: It's 1mm thick and I think that's the minimum for the trays. It's quite wobbly, but after adding balsawood it becomes much more rigid.
No problem, I can help, as far as I am able. ;) I tend to work spontaneously and without any fixed guidelines which makes recreating difficult, but I will try to describe it to my best ability.
I start the metal parts by painting them boltgun metal - dark silver color, now it's probably named differently. When that's done I wash them. I create my own washes by mixing normal layer paints with Vallejo Glaze Medium - helps with the flow and slows the drying time, but on enough textured surfaces as here with the skeletons, water should also suffice. First I made a brown wash - mournfang brown or bestial brown, maybe with a bit of black added with enough water to be about as thick as milk. With this I was all the metal parts rather generously. Then I add orange/yellow into the mix to make it a little bit thicker and more vibrant - rusty, orange colour. This I apply to the most recessed parts, where you can expect that water would gather and make the metal rust more. Sometimes I added this quite randomly, especially on the shields, to make them look good better, so sometimes follow your gut feeling here ;)
When this dries, you have a deeply rusted metal. With my skeletons I added additional highlights with mithril silver - the lightest of GW silver colours. I drybrushed the rusted metal with it which makes an effect of bumped, scratched-off rust. I guess thats optional, depending on what you need.
And that's it. Not very difficult, but maybe hard to describe.
I hope that helped.