I'd guess that the kit is universal for a lot of different mopars. I'm sure the knob on the left is correct for rallye dashes. I haven't seen many standard dash knobs, but it looks like they also use the one on the left in your pic. I'm not sure what mopar the knob on the right is for.

Of the standard dash knobs I posted above, clearly the standard knob in the rallye location has been fiddled with, but the 74 Challenger was bought new by a father and inherited by his son. The son repainted the exterior only in the original color, other than that and maintenance items, it is untouched. I couldn't say for certain though that the knob didn't break and get replaced like yours as one of the maintenance items. Do you still have a piece of your original broken standard dash knob? Which style is it?

Tav