Hey Steve - Coming home from the Vintage last year Tom (BMWSKI) lost a his driver's side wiper in the deluge. We moved his passenger side wiper to the driver's side and put some wire around it to get us home. Tom then came up with a pretty nice fix for this. He removed the wiper, flipped it over and drilled a hole straight through the top of the area that secures the wiper. This hole was directly in the center of the portion of the arm that goes over the pivot. He then installed the wiper on the car and used the hole in the arm to drill a hole in the center of the pivot, threaded this hole, and installed a black screw straight down into the pivot.
I have my wipers safety wired on for now, but plan to implement Tom's fix at some point.