For a while JC Whitney sold an electric powered wiper done in the usual "universal" style. 6 volts, and the wiper was notable in having a threaded shaft which the wiper shaft passed through.
One took off the keeper nuts, passed the threaded shaft through the 82A hole, and then used the hex nut on the outside to keep the wiper motor from turning. The base of the motor had a low durometer rubber "seat" which kind of conforms to whatever the motor is seated against and this aids in keeping the motor from turning.
Here is today's equivalent which is conveniently available on ebay at
https://www.ebay.com/itm/FORD-VINTAG...9/282961853843
He says more than 10 available.
Joe K