Needs nothing. Except for an a/c recharge.
Well, go ahead with your recharge - it will leak out again, until you fix the a/c system. Which will be $1500. Which also explains why it hasn't been "recharged".
Silk smooth engine? SPORTY??? RARE and highly sought after? LOL!!!
The MB dealer THINKS the head gasket and harness are done. That means there are no service records from the original owner. And I am pretty sure, what MB dealer THINKS is also not available in writing.
Seller is trying a little too hard to sell this, at a premium nevertheless. I'd entertain it, but definitely make sure you cut through the BS and don't take any of the seller's claims at face value.
G