Here's the grommet you're looking for:
http://www.classicparts.com/1947-53-Wiper-Control-Link-Grommets/productinfo/67-661/#.Ujm0myko6ig And as far as the operation of the wiper motor, the piston or
paddle as some prefer, dries out over the decades and needs to
be replace with a new one. They are not available to the
general public any more and the only one that I am aware of that
can replace it is the Ficken Wiper Service aka The Wiper Nan at
http://www.wiperman.com/ You are going to hear dozens of reports about how some guys
disassembled their wiper motor and re-greased it and it works
like new now. I don't believe any of it. When the wiper was new
it would pull with enough power at normal vacuum to handle most
weather conditions. Don't expect it to clear snow from the
window though. Again, the piston fabric is impregnated with an
unknown substance and as it dries out it will not make a vacuum
tight seal. Vacuum is low volume so for it to be affective in
such a small chamber it has to be 100% vacuum tight, from the
connection at the manifold all the way thru to the motor.
Denny Graham
Sandwich, IL
