I picked up mine off of eBay.
GC carries some again in stock (GC being a brand of tools/chemicals) which is what I ended up with. It's double sided sticky so you have to clean one side with a little Goof Off/Goo Gone to get the adhesive off. Be careful not to mess up the adhesive on the back side.
This only works for traces where you wrap the copper tape around the edge of the board and fasten it/solder it on the top and bottom sides.
For repairing a trace that is NOT the same on the top/bottom of the board you want to use some kind of epoxy with the copper tape instead of the adhesive it comes with. The adhesive isn't strong enough to hold the foil in place on just one side of an edge connector.
DO NOT USE SUPER GLUE TO HOLD COPPER TAPE IN PLACE!
They are a "cyanoacrylate" - Guess what "cyano" is? The fumes are harmful when you apply heat from a soldering iron.
Raymond