K&S and MSC each sell brass bar stock that you can use to make a new drawbar. I've done this a couple of times. You'll need a drill, a file and a small metal saw. A Dremel tool with cutoff disc makes the job quicker and easier.
3rd Rail drawbars are 3/8" wide and (of course) nobody sells 3/8" wide brass strips, so I buy 1/2" wide, 0.064" thick brass and cut it down.