Vintage Antique Alphabet Frame Animal Children’s Art Picture Made of Wood

This is an antique alphabet frame made of wood with the ABCs around the frame.  The picture is of a delivery truck, a donkey, and dog with a bird.  It appears to be glass over the picture.  The back has a single strip of wood holding it in.  The colors are good.  I think with a good cleaning it would be better but I do not want to take it apart.