where do I find one of these

On my sons 73 Dart Sport he has a windshield washer that is the pump style that you pump up with your foot by the dimmer switch. This little piece mounts to the cowl under the hood and has 1 rubber line into it and 2 lines coming off going to each nozzle. the pieces broke off due to being brittle so I need a new one. where can I find one or does anyone have one that isn't brittle. Thanks,Bill