Hi, I think you want this page - The 200, 200D, 230 and 230S models
The W111 finnies had a few phases through their life. I will do my best here but hopefully others can add to it.
- early ones in 1959 had torsion bars for the bonnet and boot, and wood trim on the doors, and a different front axle/crossmember. This was short lived before springs, metal trim, and revised axle came in.
- at some stage the 220S carbs changed from twin solex to twin zeniths
- the cars had drum brakes all around as standard until mid-'63 when they got the front disc brakes.
- in '65, the W108 series was coming out. The 220SE and 220S was dropped. The 220S became the 230S. The 230S lost some of the wood inside, particularly around the door glass. The 230S also only had the twin zenith carbs - there was no fuel injected 230SE model (only the W113 pagoda got an injected 230 engine - the 230SL).
- in around '68, when the W111's were close to the end of their life, the interior got updates to things like the inner door handles, steering column and wheel, and I think seat belts and mirrors more like the W114. Some consider these late cars to be the best.
There are all sorts of opinions on what is best (FI vs carbs, solex vs zenith vs weber) - all I know is that a well maintained and non-rusty car of any variety is better than a clapped out rust bucket.
Happy hunting, Drew