Scott,
I understand where you're coming from, but I think those kinds of notes regarding condition, marks, removal of marks, etc should be stated by the seller, not the authenticator (for the reasons David mentioned above).
I also think that whoever removed those crop marks should have either finished the job or left well enough alone. (I'm saying that under the assumption that the white marks that are left are white paint that was around whatever marks or framing was removed). As it is now, if the new owner decides to go ahead and complete the "clean-up" job, the photo will no longer match the image on the LOA