To clean the greasy vinyl elastomer that oozes over time from the dashpad, I just use a normal grease cutter such as Purple Power or similar in a wet cloth and wipe it down. Afterwards I put a vinyl lotion treatment on it to preserve its lustrous look and feel such as one from 3M. Whatever grease cutter you use, try it on a portion of the dashpad such as under the lower ledge to make sure it doesn't affect the pad in any negative way. The various dashpads Chrysler made were not all alike and the 1969-70 dashpads seem to have a lot of the elastomer in them while others seem to have far less without an oozing problem and they tended to crack very early in the life of the car if exposed to the sun any significant amount of time especially.@jet1969 — with Leatherique, you should be able to get the leather back into a shape that you like.
The C-Y dashes seldom crack (good). The goop that protects against cracking tends to get out over time (not good), it but can get cleaned up (good).
@saforwardlook has commented (in another thread, 1-2 years ago) about how to get the imperial dashes cleaned up. Let me know if you can’t find it.