I don't know the part number having just sold my set of switches to a forum member. You have to replace both switches idle & WOT, they are wired together. I had original replaced my switches without removing the throttle body but found I could not get the idle switch set correctly. I removed the throttle body complete and this made setting both switches far easier and when I drove the car the difference was clear! Cam combined with missing idle switch was making for a very lumpy drive. Another point to note you can no longer get the gasket throttle body to inlet manifold but it is easy enough to make your own.
Not quite true. I bought some just last week from VW: 037133073A A tad less than 4 inc VAT. Throttle body change is quite easy. Four Allen head bolts (6mm bit). Might be a bit tight if it's never been off before.
Yep. But if you haven't already unplugged the wiring to test the switches at that point, are you really sure that your problem is the microswitch and not the loom wiring above the exhaust manifold?