Okay. Keeping in mind the Pershing is a "what-if" IDF tank, I went with the T24, and am prepping another base for the Pershing, still "urban", but more regularly-sized stones, to be colored lighter.
This is the T34, on the base after adding some dirt clods and dust from pulverized clods, trying to hint at the passage of several dirty tanks through the same place:





Forgive the poor pics, Poo-bucket does not want to link edited and cropped pics this morning.
Thanks all for the input, it's appreciated.