The left one is most definitely 2009... There are more guns!!!
Correct.
Well, as of now in the progress of the game, the right one has more guns (you use the number keys 1-5).
I decided to finish the unfinished game, and ended up scraping the entire thing and rehashing a new system. If you'll notice now Mario has to pick up the weapon, and what more he can now hold a second weapon on his back!