Stepdown radio

I've got two radios here and I'm not sure what year they fit. The face that sticks through the dash looks to be the same but the case construction is different. One has a slanted piece and the other is flat. Also, it looks as if the grounding lugs are on opposite side from each other.

They're both the round button type so i can't imagine they are too far apart in model years, but I am going to be selling these off and need to know what years they are for.

Thanks!