Here's the real thing for your brakes, original Weinmann housing in black. I think there are some Schwinn sellers on Ebay that could sell you some grey stuff (original Weinmann housing - buy the 'Schwinn Approved' stuff to get it ...)
- Don Gillies San Diego, CA
P.S I've put together a 'NoPagnolo' (no Italian allowed) bike before, I know how tricky it can be to get stuff from a particular region to fit a 'mission theme' in building up a bike ...