Ariane 3 kit resources
The Ariane 3 is an improved version of the Ariane 1. Featuring a stretched third stage and two strap-on SRM's, it significantly improved payload weights to geosynchronous orbit.
The Ariane 2, without the SRM's, actually came later.
The model stands 13 1/2" tall and comes with 15 parts, decals, and instructions.
Ariane 3 Kit Instructions
The Ariane 3 Model The Ariane family lineup
You may be wondering what happened to the Ariane 2. An Ariane 2 is an Ariane 3 without the strap-on SRM's. Easy to build...except that your decals will be wrong. The only Ariane 2 photos I have (not good ones) show markings very similar to the Ariane 1, not 3.
So: to make an Ariane 2, get the Ariane 3, but ask me for a set of decals for the Ariane 1 instead. The only thing wrong will be the launch number; any set of number transfers or decals should have those in the appropriate size. If there is serious demand for a set of decals specifically for the Ariane 2, I can do that...but I suspect there isn't.
ESA Launchers web site
Ninfinger's Quick Look review of the kit (Sven "Ninfinger" Knudson is an independent reviewer).