RE: Rear Wiper on an '85
My '85 Westy (GL body) had factory rear wiper.  When I got my '90 Westy I
though it strange there was no rear wiper then noticed that there was a rear
washer!!   Turned out the DPO had removed the wiper, spot welded a piece
over the hole in the hatch, filled with Bondo before the current paint job.
All the wiring was there so off to the bone yard, picked up the whole
assembly including arm and wiper.  Easy install after having a bitch of a
time getting the spot welded piece off, actually drilled through.  Back to
stock and working fine for rour plus years now.