Your probably looking at finding New Old Stock or a used one in good condition.
Get the '67 Plymouth or Dodge parts book and look up the p/n.
Then hunt by part number.
Beware of places that post OEM part numbers but then sell "one size fits many" replacement. :(
Also put up a wanted ad. Make sure you get photos and dimensions before you buy. Some sellers really know their stuff, what it came from and what else it came on. But not everyone has that level of expertise...
Something about hte cable attachment changed after '67. I forget what and its late... maybe the firewall clip.