I would just send it out. Or if you think you may actually need wipers one day get an electric motor. The vacuum wipers were OK in their day, but there is a reason they aren't used any more. And unless you are completely set on originality, this is a safety item in my opinion. That being said, I try and try not to drive my truck in the rain period, but as I live in Seattle, you can imagine how that is working for me. (also why I have electric wipers.) You can use the dual diaphragm fuel pump and vacuum canisters if you like, and get decent performance. I did for many years, but the electric is so much extremely nicer. (at least for me)
