I have been scouring the world (so it seems) for a replacement radiator coolant reservoir for my 1989 Mustang (4 cyl.), but nobody makes them and I can't find one that doesn't leak due to brittleness. There are after-market radiator reservoirs for the 5.0, but not for the 4 cyl. We tried patching the one I have with epoxy, but the tank is too brittle.

Any ideas where I can get one? Thanks!