Good afternoon. I need to look into rebuilding my 70's era Atwood surge brakes. My question is weather or not rebuild kits are available for the master cylinder. You can see in the pics that it was pretty much a mess when I got the cap off. The rubber plunger is basically melted. I'm open to just replacing it, if a direct replacement is available. Ill probably need new wheel cylinders also, but the lines are in good solid shape. Looking for advice on how to handle it if I can't rebuild/replace.