My 300SEL had a new transmission with the PO; also the cylinder head was rebuilt. It now has 130,000 miles or so (218,000 km).

You definitely need a PPI before you touch it, even at $2500. You 'might' need front end, trans, engine head, brakes, shocks and who knows what else. That windshield is expensive - see if you can get the owner to make a comprehensive claim. Plus, it will need a tune-up and perhaps a chain, if it has not had its oil changed regularly.

All that stuff is doable if you are handy, but a 'new' trans will be about $2000.

The oil leak, unless it is a rear seal, will just be a nuisance.

__________________
1991 300 SEL
218,000 Km

"Xsbank's rules of mechanical intervention: Always go for the easiest solution first; 90% of what ails a gasoline engine is ignition; After that its all a WAG."