Pen drawing of bullfight

This is a beautiful drawing representing a bullfight. The work was done with crayon over carton. It was framed at one point, but as you can see in the last image the passpartouts covered a good part of the drawing. In addition, it created a shade effect on the covered area. The piece is mailed without frame. The work measures 63cm wide X 50cm tall. The drawn "as" on the bottom right corner could be the artist's initials, however I feel that it more likely stands for "artist study". It would look great in a black frame. Thank you.