190 SL has been sitting for 24 years

[S Nieman]

I was hoping for some good advice, I did a search and could not find any info. A friend of mine's family is selling their grandpa's 1956 Mercedes 190 SL. The car, from what I am told, is in pretty good shape. The car was running when he parked in his garage 24 years ago, he rebuilt the carbs and then he never started it again. Now, Grandpa is in bad health and they are selling the car, I told him I was interested.
If I decide to take on this project, What steps should I take before I try and start the car? I am going to Change the oil, new spark plugs, empty the gas tank, clean the fuel line and new battery. Is there anything else I should do to make sure no damage is done to the motor?
Any tips or suggestions are welcome.
Steve