LWB- they wont allow the car to be brought to a shop. Only way to PPI is by sending tech over. NEw York City area. Know anyone ?
RUN, do not walk, away from this as if your hair was on fire.
The minute a seller tells me they won't take a car to an independent shop for an inspection I'm done.
If I was spending literally tens of thousands of dollars for a car like this, I would expect the seller to be accommodating. I can understand why they would not let you take it, since you don't own it, but if they won't drive the car or arrange to have it driven to a local shop for an inspection, my BS meter goes off the scale.
I'm merely making observations here based on the information you've given us - my comments are not a personal attack, and please don't take them that way.
If you buy this car you are out of your mind.
You don't appear to have done much in the way of due diligence as far as this model is concerned. Buy a copy of John Olson's "SL" book and read it in depth before you buy one.
You're looking for a "deal". Cars like this are not found as "deals" unless you're planning on a restoration. The ONLY way to buy a car like this (and I am speaking from direct experience) is to buy the very, very best example that you can afford. Buying a "fixer-upper" will cost you far more in the long run, even more so if you're not familiar with this model and its idiosyncrasies.
If a seller is not motivated or accommodating enough to arrange for a PPI, they're hiding something or they aren't that interested in selling the car. The minute a seller balks at a PPI, regardless of the reason, should be a MAJOR red flag to a buyer. I have felt this way whether it's a $1000 car or a $10,000 car. If the car is fairly represented, a PPI should yield no surprises.
You don't sound like your "all in" on this. If I was to spend $20k-$30 on a car that's 50 years old, I would study everything I could, ask lots of questions in the forums, and talk to some owners and even try and find a few I could look at and drive, if possible. Then, and only then, would I start to look for a possible candidate.
These are not the kind of cars you buy on a whim, unless you have a lot of disposable income. As pointed out earlier in the thread, just sorting the subframe bushings will easily set you back a cool $1000. And that's doing it yourself. If you're not capable or skilled enough to do the work on the car, it's going to cost you that much more and you're going to be at the mercy of your local MB mechanic, very few of which will touch these older cars or even have knowledge of them.