I do not know much about the engine of a 320 other than it came after the 300-24 valve and that is an engine which is very well known for its oil-leaking problems. I've got two cars with a 300-24 engine with about 110k km's and oil-leaking problems. They do not leak much and are quiet simple to repair, but since I rarely use these cars I did not find it necessary to do something about it.

The SRS light can be put out by the dealer. You need to plug the car to a computer to have a look at the detected problem (can be a disconnected dash-cluster for bulb changing whilst the ignition key was turned) and to reset the system.
This can hardly be a big problem and can be reset by any dealer within 10 minutes.

greetingz & good luck,

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1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)