“Be wary of copyright infringement.”
That would be my worry as well. I would take a couple of samples to a local artist (Maybe a art student who could use a couple bucks)or find a suitable picture of Woodrow Willson in a top hat and glasses, plenty of those around and all should be in public domain. Then you could use any number of free photo software that would allow you to turn it into a drawing. Hey how could using a picture of old Woodrow as a free spending socialist not be TRUE!!!