For your consideration, here is a Vintage Checkmate 1700 LED Calculator, made by Litronix, serial no. 39843, made in Malaysia, with case. Please note: It is non-functional for batteries. One of the battery posts is missing a metal piece. It does take an AC adapter.  I have not tested it with an AC adapter though. 

The calculator has wear on it. There is a spot under the MATE where it is missing small spots of the finish. The case has a little wear on it. Item pictured is the actual item up for sale and comes from a non-smoking household. (204.279a-.9hc)