The frame would be the same throughout the model range. R2000 vs r600 or whatever, all the same. The only difference is components and maybe the fork. I can't tell from the pics what the components are but the crank is not a Dura Ace. As has been said the fork in not original. They've also switched to bar end shifters. Nothing wrong with them but not generally on a race bike. They're easier to find and cheaper too. Looks like a 58cm to me but the serial # makes me think it is a 56cm. That price seems ok but I'd want to know more info and specs on the replacement fork.