I would not buy without records. This is not because of a few missing oil change receipts.
If you start with the assumption that there are predictable failures along the mileage curve, then doesn' it make sense to buy a car that has already had those items replaced?

Now if you are buying a farely low mileage car then those items most likely will not have failed. My approach on the last three MB has been to find a car at about 100K that fits the already replaced pattern.

For instance, my most recent purchase, '97 S320 Dealer serviced with 109K and all records. So it's had head gasket at 67K, MAS, Blower Motor Regulator, window regulators, seat belt assembly, battery, charcoal filter, windshield at 102K, rear rotors, new outside mirror. It's thousands of dollars.

'92 300E bought at 113K had something like $ 9,000 of receipts within the previous 12 months. It was serviced to death throughout it's life. Currently has 245K and it's consumed a fair amount of maintenance dollars out of my pocket.

So for me it's records, records, records. There are a lot of cars out there, why not buy one with records? Forgot to mention paint. That is the item that is pretty much not fixable, unless you want to fork over 5 to 6K.

Steve