Making new shelves for cage: help!

Hey guys! Today we got our first ferret nation cage for our chins. It was pre-owned by my niece and we got it for free from her. We cleaned it three times thoroughly, and then started construction on it to make it "chin-safe" and "chin-proof" because my chins are EXTREMELY good at escaping
I have one homemade shelf and a set of 4 homemade climbing pegs, and one of the original ferret nation plastic shelves (that we're going to cover in anti-pill fleece.
We made a false bottom out of wood...

Making new shelves for cage: help!