I'm for keeping the look, and texture about the same throughout the engine area, with certain exceptions. Things that are sand cast, like the intake and exhaust manifolds cannot be polished, but you can smooth them out to a point. It allows water to drain, so you have less to clean for show. Things that can be polished like crazy, such as the rocker box, AAV, carbs, tubes, etc., get more hand-work and possibly some shiny plating. Rubber should be supple-looking, like when it was new.As for the billet parts- I usually only add them as required to replace parts that are worn out or 'broken' but would keep with the texture an sheen of the surrounding or similar OEM parts. That is, except for the occasional 'decoration' which might be very shiny or have some color to it ( like a red radiator cap or spark plug wires.) But I would like to see something (not everything ) with a Z emblem or just some nicely printed letters ("Stant: 15 - 18 PSI" or the ubiquitous "Danger: fan" decal on the fan shroud.)
As for the motor, it is painted black as it was from the factory.