Has anybody figured out a "good" way to fix this?
The pawl that screws onto the control box mechanism is broken off of my control cable and I can't seem to come up with a way to fix it. Its the only leverage point to hold the cable in place to switch between heating and cooling...

I have a 1968 convertible, 289, Auto tran, Factory AC...Lime Gold w/Light Parchment interior
Have spent the last 6 years rebuilding it...will get some photos up soon

 

I'm not exactly sure of what you're referring to. Can you posta picture?

However, about a year ago I broke the plastic piece that clamped the cable housing to the control panel. I'm guessing this is the same thing you're talking about. I certainly couldn't figure out how to fix it with glue/epoxy/etc...

I ended up buying a set of new heat, vent, defrost cables (3 for my 67 w/o ac) for about $30. The only place I could find that carried it was something like John's Mustang out of Texas. I'll see if I can confirm that is the correct place.

I had to stand on my head to hook up the new ends to the heater plenum, but it works great now. Also, if I recall correctly I think the replacement was metal instead of plastic.

Good luck.