[OS X TeX] [Slightly OT] Crop marks over a full page image

[David Watson]

I am currently in the process of compiling a book of abstracts for a meeting-in-miniature.
For this work, I am using the document class memoir.
The printer want bleeds for the cover page of 0.125 inches, and crop marks, which I've figured out how to do for the remainder of the document (resetting the \stockheight and \stockwidth and using \settrims.
The cover page is a real doozy, however, because the bleeds cover the crop marks.

I am using pdfpages to insert the cover artwork, and it works for letter size pdfs inserted into the document, but not for the full sized pdf cover.

Does anyone have any experience or any suggestions for placing the pdf (or any other image) BEHIND the crop marks?

They require pdfs and asked me to submit bleeds of 0.125, although the trims I suppose could be any size.
Any ideas?