Aaaannd, I HAVE it! Thank you very, very much delpart! The clouds are a red herring! All of the magic actually happens on a different layer!
I was working in multiple layers and doing effects to see what would happen to the whole image (perhaps not the best way to go about it). I certainly had the cloud layer, but it was only an overlay. It was in the flat color layer beneath were the magic happened:
New layer > Paintbucket light gray (808080) > Add noise (Intensity 60, Coverage 30) > Splinter (Splinters 9, Distance 12)
VIOLA: Elephant skin!
Add layer (Overlay) > Clouds (404040 and 808080 is my favorite)
VIOLA: My red herring texture!
I was trying to go for a mud crackle effect (thank you for THAT link, delpart), but was unsuccessful. So I was playing/hunting for ANY kind of organic cracked effect. I hope this impromptu tutorial helps some folks--it's only a small way I can pay you all back for such a great program and site!
JOKE: When do clouds look like an elephant? ANSWER: When you look for mud!