Date registered: Jan 2006
Vehicle: 73 280SE 4.5, 71 300SEL, 03 BMW Z4, 72 Fiat 850, 80 Triumph TR7, 85 Porsche 911
Location: DC Area
Mentioned: 1 Post(s)
Quoted: 97 Post(s)
Doesn't look too awfully bad to me. If surface rust hasn't set in, a thorough wash will do wonders. You can also buff/wax the paint with an orbital sander and it'll probably do wonders.
As far as the engine, expect about 17mpg, tops. Anything less on the highway and you have tuning issues. I'd recommend getting rid of all the old gas, inspect the gas tank for water or rust, change the fuel filter and gas tank screen, replace plugs, wires, etc, and give the beast a good run.
Another thing you might think about is having an electric overdrive installed. Yours is a three speed and highway RPMs will be high. I found a place in LA that does these things for about $2000, but I'm stationed overseas, and Denver is home. Once (if) I ever get home, I'm going to have one installed.
As far as spending a lot of $$ on restoration, consider cleaning the interior and exterior very thoroughly prior to doing anything spendy. A whole new interior (seats, carpets, door skins) will run you about $7k or so for parts. A dash pad, to cover the already-installed one, will be about $100 off eBay. Except for your driver's seat, your interior didn't look that bad. If nothing else, you can redye that seat for under $50, or cover it with sheepskins.
Labor, having wood done, etc will differ from place to place.
One thing to think about is getting to know your wrecking yards well. You may find a gem here or there. When I was stationed in San Diego, I found a 108 that had been rear ended, but everything else was in great shape. I spent the afternoon taking all the interior wood and a few other things I wanted as spares.
A tranny rebuild, thru Aamco, once cost me about $2000. A new engine, not counting accessories, will be about $4500 (no idea how much a rebuild would be). The ECU will run $500 -$1000 rebuilt, depending where you look. Again, a pick apart yard might yield good results as well. Most of the parts I've ever needed for my 108 were available locally - try Napa, or Kraegan, O'Riellies, etc. Mercedes still stocks parts for the older cars, but they tend to get expensive and (in my opinion) offer no value added.
Mercedes produced a zillion 108s, so doing general internet searches for parts will yield good results too.