Well, I had Al check the car out and the results are great.
Compression: 320 on all 5 cylinders
Items needing repair:
Oil pressure sending unit leaking - $45
Injection pump leaking (bottom plate) - $240
Steering return hose leaking - $60
Motor mounts collapsed - $320
Differential mounts bad - $275
Power steering pump leaking - $350
Everything else on the car checked out fine, and Al did an extremely thourough inspection. The estimates he gave me on repairs include parts and labor, and are quite liberal. Al likes to estimate the largest possible charge so there won't be any surprises.
Excluding the oil pressure sending unit leak, none of the repairs are urgent. All of the leaks are slow. They amount to a drop or two coming off of the bottom engine cover every couple of days.
I checked at the local MB dealer, and the owner has had it serviced at a MB dealership every 2500 miles. I would have bought the car today, but there was a problem at the bank. I should have it tomorrow or Monday.
1976 300D (W115) - 330K and still going (sort of)
1991 300D 2.5 Turbo - Sold at 221K
1983 280SEL - Sold at 206K
1981 300SD - Sold at 232K