I have a old Sears and Roebuck model - 213.57 incubator that I found when my mother in law past away. I would like to sell it. I haven't been able to find much about it. I have the orginal box that it was mailed in and the instruction manuel. I know it's from the 1950ies but that all I know. I looked on Ebay and I couldn't find any information, on it's value. Can anyone tell if this is considered an antique.