Let me begin this post with a rant.
The best and worst thing about the Gundam: The Origin line of model kits is its abundance of Zaku prototypes and variants. On one hand, I love that the Origin OVA basically forced Bandai to make kits out of mobile suits such as the Waff, the Bugu, and the Zaku I. I also love how you can get so many of these kits in different colors, such as in either standard green:
Char Aznable red:
Or the black/purple scheme of the Black Tri-Stars.
In the past, these kinds of mobile suits were either too obscure or too specific to see frequent release, but in the Origin OVA’s they are, in some cases, the only suits to show up during a given episode, so Bandai had no choice but to make new models out of them.