This is an assembled and painted Faller 1/100 scale model kit of a World War II German V2 (or Aggregat 4) Ballistic Missile.  The model of the missile is complete; the trailer, tractor, launch stand, and erectable part of the trailer are mostly complete. There seem to be no plans available for the Faller model, but using the Revell plans it appears that a few accessories, like shovels, ground crewmen, and part of the extendable hydraulic pistons are missing. (The remaining piston stubs are glued in place  -- they do not move.)

The original boxed version by Faller contained 4 models: Fi-103 - FZG-76, V-1, and V2, but this offering is only for a built V2.

The identify as a Faller model is based on the scale  --  the missile model  is just under 6 inches tall,  which makes it about 1/92 or 1/93. A very similar model was sold under the "Hauler" brand, with an advertised scale of 1/87, or true HO gauge. Scale assertions in the early days (say 1959) of plastic model production were a little "iffy", so this could be a Hauler brand.  However, the Hauler model did not contain the launch tractor, gantry, and stand, so my best guess is Faller.  Incidentally, this model is close enough to HO to be used in an HO setting.

The color scheme is colorful, but not as fanciful as it at first appears.  Camo standards for V2's were vague at best.  I included a couple of box art examples of color schemes:  However there is no box with this kit.  The box art is borrowed from the Internet to give you an idea of how the model should appear.