I have inherited a steel engraving of Catherine II (unframed, approximately 12″ x 15″). Please help with any information about this piece, including the signed names, which appear to be Rotari and Guttenberg. The name of the hotel (in French) reflected at the bottom of this piece is perhaps where this portrait was done? I am unfamiliar with the process and meaning of “steel engraving”. Any information regarding this piece, including its age and value, would be very much appreciated. Additional photos are available upon request. Thank you.