The Original Hehr operators have a cast pot metal gear that strips out, causing the crank to fail. I kept all my old ones in hope of finding a way to replace or recast the gear teeth back on at a later date. In the mean time, replacement with a new generic unit is the only option. I obtained them from Blaine Window Hardware, and the part # is 00821-7. They are not cheap at $18, but inoperable windows aren't an option either. 

On the left is a replacement Blaine opener with the Zolatone texture finish applied; the center opener is the Blaine with just the base coat of the Zolatone; the right opener is a Hehr original with the Zolatone finish restored.

The left opener is original, the right a replacement Blaine unit. You can see the Hehr logo on the crank.

These are the sliders that the arm of the opener attach to that slide in the channel in the window frame. The upper is an original, and the lower is a replacement made using a 10-24 fillister head nylon machine screw & nut. Sand the screw head down on two sides to 1/4" and the nut on two of the flats to 5/32". Cut the screw length to the inside width of the frame track.

To reinstall, insert the rod end of the opener through the slot by the window. Insert the hole in the opener rod end over the screw shaft & install the nut. Place this new slider into the top of the frame track and then attach the opener to the window with the two screws. Lube the slider and track with a little Lithium grease.

August 2006: GREAT NEWS! Exact Replacements are now available fromn Vintage Trailer Supply.

Next we will talk about the curtains and tracks