Read 4th paragraph here:
https://www.hamtramck-historical.com/images/vintage-advertising/1974DodgePressRelease/dartse3.jpg
Mentions choice of two grain finished on either Black or Parchment tops. I wonder if the "P" was for a choice of textured grain top. It's just a guess.
You need to find info given to dealers on how to order a 74 Dart S/E or find someone with that V1P code that still has the original top.
the 1974 Dart S/E was a mid year model. So all that info would not be in the literature published at the beginning of model year.