converting to nurbs can be good for avoiding the time needed to UV map but have you tried projection mapping? Especially for some of the smaller parts, I think you'll get some nice results from building your shading network up in the hypershade using layer textures and projections (set to triPlanar) and if needed you can always convert to a file texture if render time (reading all those nodes) becomes an issue. Its not everyones prefered technique but it works well in some cases

Keep it up
J.