From the photo and the badging, I'd say it's a 1989 model year. Confirm with the VIN ("K" in the 10th digit). I love my '88 260E and it's plenty peppy, particularly for in-town or cruising the Interstates. One possible noticeable difference from your 300 is lower gearing in final drive. It uses a 3.27 rear end while the 300 uses a 3.07 (IIRC). One other issue that blue cars have is that the blue dashboards seem to be particularly prone to sun cracking. Otherwise, very solid driver.

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't