A little update, as the deadline is near (I've done this quite a while ago, just didn't get to upload the pictures and post on here. Besides that, I've done more in the meantime, but didn't take pictures of that yet. So long story short, here's a n update, but the progress in it is not recent and doesn't refelct the current state)
I glued the wood on to the coffee cups-made base. I filled the gaps between with wood filler.
I glued some sticks together, and cut two circular shapes matching the ends of the keg.
These are now attached. So, all I have to do is making the cart and paint. Well, and pray the beats which will pull the whole thingy will arive in time