"Hehe. That's not the original, untainted, version of the model. The nacelle caps are replacements, as well as the deflector dish I believe. There are some studio sized replicas out there that look fantastic that could pull it off."
Well, it is the original and untainted version, where unfortunately the original nacelle caps, sensor dish and lower saucer dome (I believe upper one, too) had gone missing but I might even prefer this one over the CGI version.
Of course CGI has the advantage that you can seamlessly close in onto the ship like they tried to the old fashioned way in The Cage
and beautifully fixed it for TOS-R (I presume the opening shot from TNG's Encounter at Farpoint
will receive such a treatment for the special edition of TNG somewhere down the road).
In general I found the CGI close-ups in TOS-R rather boring giving us nothing else then sterile corridors behind the windows so I'm currently working on deck plans that may give you a little more interesting stuff behind these windows in case a future TOS-R Version 2.0 will also be done with CGI and is looking for some ideas: http://www.trekbbs.com/showthread.php?t=195496