Have it repaired. Most likely the pot. If the signal is going through it is about the only other thing besides the inductor that would cause that. Since the pot is used constantly it is where I would...
there are so many different ones!
the cheapest one i found was 43$ (behringer uw300)
the most expensive one was 623$ (z.vex ooh wah)
but i can recommend a dunlop cry baby for about 110$ =]
That's a good question, he uses a wah-wah during the receding parts of his notes...but you wont get the exact same sound as he does it without a wah-wah. but the best thing you can do to get it close...