Interesting drawing, that one. Very period treatment (sloping shoulders and ruff stylized, exaggerated) but proportions make me think it was an artist with some experience, working in an intractable medium. I wonder if the letters and numbers are lettering practice? I'm an artist, and you'll find scraps of paper all over my place with no actual content, just practice. But I can't see the letters in the drawing to see if they are crude or have any style to them. Anybody have better eyes than I do?