'91 differences (from your '87)
1. Button on dash to control antenna deleted ('91 only)
2. Interior paneling of doors updated to a ribbed design.
3. Speakers added to door panels (front only)
4. Button which controls horn tone moved down in between seat heater buttons.
5. Seats up dated to a more modern look, as oppssed to the previous "pleated" traditional mercedes look.
This is all that comes to mind for now. Check out ebay for pictures which will show the differences.
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.
1973 220 (gas)