I can't say I've seen from the factory 4-speed consoles in 70-71 darts but they were very common in the 77-80 Brazilian darts and the Mexican chargers. All were 318 cars. The tach in your picture is a 67-68 tach but I'm sure you know that. Joel Cooper would know for sure, get ahold of him.
Joel is an old friend and the fact remains that the 4-speed console and shifter handle are included in the 70-71 Chrysler parts manual, so they had to be available. However, I have never seen any. All that I have found so far were added to them somewhere along the line. It is not an easy modification as brackets have to be welded to the floor, and if they were originally automatic cars then the shifter bracket has to be cut off.
