So it would have taken some effort to create the E, L and A. Unless the font at that size was in common decal use in other model kits of the time, perhaps? Thanks for the information!
E N T E R P R I S E
C O N S T E L L A T I O N
Whoever did it would also need a C, and two O's, unless you think the decal sheet had the word "Constitution" on it, which it didn't.
Nope, the ship's name would have been generated from whole cloth. I suggest it was made from dry transfer letters purchased from a blue-printer somewhere in L.A. And just the registry number was rearranged kit decals. After all, why buy a second sheet of letters in a different point size when you have perfectly good characters waiting to be easily cut up and rearranged?
Nope they didn't. What they did, they painted the extra missing letters in. They didn't bother with the nacelles and below the saucer. The nacelles would be damage in the area of where the registry would had been. Plus they only plan to film her from above, port and aft. They never filmed the model from the starboard side and bottom. Also, I don't think they knew the registry of the Constitution during that time.