Here are some screen caps from the film. At the top we have two nice images of the Friede's
internal arrangement, more particularly the upper crew levels. From that one could get some decent idea of how things go together. This is bolstered by the next two images showing a cutaway mockup of the ship. The next image (third down on the left) shows us some underside detail---not much, but it gives me a better idea of how the nozzles fit with the bottom of the vehicle. The image next to it shows us the ship on its gantry. At first it looks like there's a band around the craft, but it's actually a collar supporting the ship for it to be lowed into launching position. The bottom pic on the left shows the ship being moved over the water tank where the film says the ship is too light to support its own weight so it is placed in water for launch. The last image shows the ship in flight after launch and I can't make out any band around the fuselage.
Unfortunately there are no other clear shots of the ship elsewhere in the film. later in the film we see the fullsize mockup of the upper section after it has landed and thats not where the colour band is supposed to be anyway. Earlier in the film we saw the miniature mockup being studied before launch and it also showed no colour band.
So from this I can only deduce that the red colour band added to the Fantastic Plastic kit was someone's personal touch to add colour.