One of the pros about this model is that all the pieces are rigid bodies and a therefore do not need to deform in any way (like the face of the Sheldon character). This allows me much more leeway in the modeling department and has thus been considerably more speedy.
Because I am being more free with the 3D interpretation of the design I have also decided to divert from the normal process of modeling, unwrapping and then texturing. I am planning to rather tweak, UV unwrap and texture pieces as I go along. This allows me to identify problem areas (such as the areas not visible in the original design that I have to freestyle), and adjust as needed as I go along.
I have also been watching some more tutorials related to rendering in Maya. Tonight I did some of the unwrapping and texturing of the three main 'henges' of the design and then had a go at some quick renders. I was extremely happy to see that some of my research has payed off. I believe I have found the perfect settings for rendering the model so it very nearly resembles the concept art. Here is a quick test render I managed to push out tonight:
Also, it seems that this setup is also relatively light on the render side, even at full HD. I still haven't cranked up all the settings for best quality and I am only rendering three textured models in the particular scene so it remains to be seen if the render times will stay low.
A high resolution test render is available HERE