moving parts

I forgot to mention one thing... if you ever do decide to join the models, you could theoretically just create a shape key of the rotation since the model is now technically one mesh. That's one benefit of joining the two parts, but that could also be somewhat limiting. It's a good alternative though if you actually need to join them for whatever reason while maintaining the point of rotation (like exporting to FBX).

I think you made a wise choice by not joining them. If you join the two parts, then rotating them at a hinge will need to be done in edit mode, obviously. However, once they are joined into one mesh, you would need to set the 3d cursor as your pivot point at the hinge location, then set the Transform Pivot to be the 3d cursor (if that makes sense). The problem then becomes, what happens if you need to move the 3d cursor in the scene? Also, you would need to enter edit mode every time you want to rotate the hinged object. It's much more convenient for animation purposes to keep the two hinged objects as separate, distinct models.

cool

Don't you want it to be all gold?