Buck,
All of the F & R Valances, L & R Rockers & Engine Lid Grill were a semi-flat or satin finish - & the 4 lower panels had a pebbly texture from undercoating, which most folks recreate with Wurth or other body shutz/undercoating (also used under the paint on the belly panels & wheel wells, etc. "down-under" BTW).
There are several threads on how folks recreated this for correct OE & CW finish over in the Originality & History Forum.
I don't know how well PC will hold up on those lower panels vs. paint over undercoating with all of the rocks & road crud hitting them, since PC can be more brittle than some paints made for that application - plus it's easier to touch-up paint with a rattle can or brush, than to re-PC them.
If you're trying for a concours car & will do PCA Parade, AACA, etc. shows where originality matters, then you don't want to PC, but do the proper undercoated then painted satin/semi-flat black paint finish as close to OE as possible today.
Good Luck!
Tom
///////