Its going to be very very difficult Im afraid.
What you need requires one to be present at the time a car is being scrapped. Like I said, mostly the seat rails are weighed off with the metal. Seats are saved if in good or even reasonable nick as they have a good market, not only for VW nuts but also a range of other (interesting) applications.
Till today, I have managed to grab only 2 pairs of seat rails, one for my ragtop project and one which I passed onto a fellow dubber (holler if you are reading this).......both required constant calls to tie up for viewing actual slaughters so one can grab what one needs. With the way things are in Karachi, worsening Law and Order by the day, it now seems next to impossible.