Yes, it is the stock one. It wasn't THAT bad I guess, I could still get 1 cm groupings at 10m when the gun was new. I guess the rubber REALLY wore out.
What hop up rubber would you recommend? I've heard great things bout Guarder, and it is available here, but only the black 70% hardness one. They also have a Systema rubber, but for some reason it's 2/3 the price of the Guarder rubber.