Thanks Maenas - they are cork and wooden sticks, painted. The tufts are static grass, a mix of green and brown.
And thanks Arch - I fumbled the timekeeping by throwing out the note and only managed to keep a rough estimate, but I don't think I was much over, so I am happy. The bases probably pushed me over, but I spent a while figuring out the Flockbox and I also gave him upgraded bases for just a little extra, so that was okay. All in all I'm pleased, now I hope to find more assignments.