Sorry if I appeared rather curt. The images in the Wikipedia site are small, have historic interest and appear to be from Muslim sources.
We are in danger of going to such lengths not to worship Muhammad that we end up doing just that. I would be more concerned about the widespread tradition of having calligraphic diptyches of the names of Allah and Muhammad as decoration. They are far more indicative of a duality or partnership than any minute depictions in historic documents.
Let's get the whole thing in perspective and balance otherwise the Muslim world will again, as it does so often, make itself a laughing stock.