Vacuum Wiper Motor Service https://www.fifthaveinternetgarage.c...ors_update.php
When you took you car in for service in those days part of the "check-up" involved servicing the vacuum wiper motor.
The mechanic would remove the vacuum wiper hose from the engine manifold and hold it up in the air above the height of the dash and squirt brake fluid into the hose using an oilcan. The brake fluid would run down inside of the hose to the inside of the vacuum motor. Reconnecting the hose and turning on the wiper motor with the engine running would circulate the brake fluid inside of the vacuum motor and soften the leathers inside of the vacuum motor.
The final job was to be sure the brass intake screen on top of the vacuum motor was free of dirt and dust. The mechanic would use an air hose and pointed air hose nozzle to blow the screen clean. Then as now the cause of most vacuum wiper motor failures is lack of use.
You can try to revive an old vacuum wiper motor by removing it from the car and soaking it in a coffee can full of brake fluid for a day or two. That will soften up the leather bellows inside of the vacuum motor. Depending on their condition you might bring them back to life. If the leathers have been dried out for too long and are cracked and separated, then there is not much hope and you will have to send the vacuum motor off to get rebuilt.
And just so you know…then as today, 37 miles per hour is the speed at which bugs begin sticking to the windshield instead of glancing off.