If you happen to find one there, and don't know how it got there, your conscience can be clear, otherwise you are fudging! But they may not know that.
Not trying to beat this to death, but it's not really fudging. I spoke with a MC inspector earlier whom I know, and he told me that as long as the truck was built to contract specs (FMVSS requirements at time of contracted build), then it's not an issue...as long as none of the GVWR, GCWR, Dry Weight, VIN, and other vital specs are altered/changed, then it's a non-issue to install the above FMVSS sticker. He told me it's most likely an administrative item that the DMV clerk wanted to see done, most likely to cover their administrative (paperwork) "bases." The MC inspector also told me that he's never looked for any kind of sticker like this when inspecting CMVs, only the appropriate data to ensure that the driver & company are in compliance and safe (VIN, weights, registration, insurance, etc...).
Are there any military vehicles built within the past 50 or so years that would not meet FMVSS requirements? Not a sarcastic question, but a sincere one...HMMWVs notwithstanding, as if they weren't up to FMVSS standards, they wouldn't be allowed on US public roadways. If the armed forces are held to the same federal vehicle standards as the rest of us (and other federal agencies), such as emissions requirements, I don't see how a MV would be exempt from FMVSS requirements. I know this has been covered in other threads, otherwise I wouldn't have suggested it here.