aaah, windshield
wipers, not washers

and the 'stops' are in the transmission link arms .... maybe simply the change to a 'standard' electric wiper setup, which was different than the vacuum setup after 58, but maybe you're meaning the ends where the long arms attach to the pivot - if you have the factory setup for 58/9 the main link arm was one piece [and labeled left/right], maybe someone changed something?
Bill