A member of the CC2 Mailing List generously provided me with a PDF scan of a section of an Undermountain II map to show the background I'm talking about. Here is a link to a smaller JPG of that scan:
I have the larger scan he made available to me in PDF if there is a way a tile could be made from a larger version of the above image as well.
Hopefully this will make it easier to get help without requiring someone to own UM II.
As always, thanks for any help you can provide everyone!