Not seen one of these before! I am presuming g it’s an original advertisement board as it has two holes to thread string/ribbon through…….also presuming it was a shop piece but have no evidence to prove this. It is slightly storage ‘dished’ with a few bumps to corners. Whatever, it’s a fab piece to hang in your vintage sewing room!! It measures approx 29 x 21.5 cms. It’s made of thick cardboard and is slightly discoloured to the reverse.