Well there's exactly no structure of the lower cogs defined so far, so this can be modelled as a very simple system of 4 linked cogs. It's even easier because each tooth covers 1 degree - so the cog turns 1 degree a day and the year has 360 days. The smaller cogs obviously have fewer teeth to fit the structure.
I can knock together a height map, but that could take a while. What would you need? I'm pretty certain there are no legal issues around it, but I'll certainly check with the people making the game. I'm pretty sure they'd be overjoyed with this!