Interlaced means that every 60th of a second, half the image is shown. The first 60th shows the odd lines of the image, the second 60th shows all the even lines. So basically, you have 30 full images a second. But you know that already.

As the movie was shot at 24 fps (not 30 fps), the “trick” to transform 24 fps into 30 fps (so that it can be carried on NTSC) is by doubling (pulling up) some frames, which you can easily remove (“pull down”) with IVTC (in AVISynth or even VirtualDub).

You won’t get additional information, image or quality by keeping those pulled up frames.