welcome to the site! Poke around a bit and once you make I think 4 posts you are no longer moderated and can PM folks. You will also be able to post in the parts wanted forum (don't think it shows while you are moderated).
Have you checked Ebay?
http://www.ebay.com/itm/Original-60-61-62-63-Chevy-Truck-Windshield-Washer-Wiper-Switch-2-Speed-GMC-1963-/311957473021?hash=item48a21d46fd:g:SS0AAOSw6YtZSahZ&vxp=mtr
When we had our 59 Suburban, I think I ended up getting one out of a 64-66. I had to make the hole in the dash larger and buy some super fine nuts off Ebay but, it was brand new instead of all old contacts inside.
