Rozalee asked an interesting question: Whether it's ok that the model keeps changing as he makes it and will not look like what he originally showed us.
But of course! That's the whole idea of making models--that you design the design as you model. After you've passed up tomorrow you will still be able to see how you could have done it differently (and better.) So don't fret...just do it... and tell us tomorrow what you learnt from the whole process.