What do you mean "maybe?" Are you making an offer on this lovely frame or not? The Fox Shock is rare, I don't think I want to let it go for that price. I still have a bike like this that I ride for special events.
All fsr stumpjumpers from this year were 19". In every size. Youll have to measure the tt lengh and headtube lengh to determine what size it is. If it has a 90mm headtube then its either one of the two smallest sizes