Could be anywhere. I've come across NOS stuff at swap meets, or buying out an old shop's inventory. Sometimes you get such stuff when you buy a car; a lot of these guys will flip the car and keep the NOS parts. There are guys in the VW community whose 'job' is just to travel and around and buy this stuff up and drag it to swap meets/flebay.
And indeed a lot of repro stuff is pawned off as NOS. There was a guy selling the repro spare tire tool kits as NOS @ the Kelley Park VW show a few years ago, before the general public knew of their availability. Another old-time VW pimp was selling "NOS, in-the-box" VW bug pedal cars on ebay, which were actually brand-new chinese made items from one of the online VW parts sites; he was getting upwards of $500 for them on ebay (retail: $99), and then just having them drop-shipped to the lucky customer's house.
Sometimes you just get lucky - I had a guy email me asking if I wanted some 'old parts' he had just aquired at an estate sale. I
still have some of that stuff, and I ain't lettin' it go cheap
