For what it's worth...

Yes it is possible for the 119 engine to jump time, although as mentioned earlier, it's often more catastrophic. Those I've seen have not been in running order. The ones I've spent time with were both damaged to the point that the engines were locked up, however, when all was said and done, they required no cylinder head work, so that might be in your favor. The parts list is long, and includes several not directly related parts, but the sort that you'll find yourself doing while you're in there (needed a water pump, perhaps air filters, sparkplugs while you're at it... that sort of thing, there's always something...). The parts lists averaged about $2400 (retail) on the last two we did. Your costs may be cheaper, but those are what they paid, and those prices are more than a year old.

For myself, would I do it? No. I would not pay more than $500 for a salvage titled car, nor would I ever buy a salvaged titled car with the intention of using it for anything other than parts. There will always be something else wrong with it... Would I undertake the job you're describing? No. And that's considering that I am a professional MBZ tech, and can buy my parts at cost. Although to be fair, I also have no desire, nor place in my life for a Mercedes Benz passenger car.

Please consider all aspects carefully, and decide for yourself, the only thing I will tell you NOT to do, is buy the car, take it home, tear it apart, decide it's too much, and then pack it all, or most anyway, into boxes and tow it to your nearby MBZ tech... And expect him to only charge you half because "you already did half the work!".

MV