an 88 with 30,000 miles wow. who owns these cars? super. hows the body? As for lowering the seat, interesting question, the seat comes out easily enough, just four little bolts (standard 10mm I think) the back passanger side bolt is a little tricky to get to. the chair will slide off the rail -for the safety belt- on the right with the cap off and there are elecrical plugs underneath, two or three that unplug and the seat comes out. with it out though (and its a little heavy and cumbersome), as posted above, there is a very thin layer of horse hair and then springs. I would bet that the springs would be the only place to really gain any height, but you don't want to cut them out... maybe you could compress them somehow, but they are kind of delicate. check online for aftermarket seats and see how they compare, perhaps you could swap yours.
1985 190e 2.3