1960 mercedes 220sb

For auction is a 1960 Mercedes 220sb. I have owned this car for several years. Was driving all last summer and all of a sudden wouldn't start. I have gone over any shortcomings I thought were causing the problem with no luck. It gets gas and spark. Will fire then backfire through carb or tailpipe. I have checked valves, ignition and fuel system. I believe the problem exists in the timing. Timing chain is in tack, but might have jumped a tooth.??? I have spent all the time I car to on it, and am passing it along. The body is extremely solid for it's age. Has a 10 footer paint job. Car has a lot of restoration potential. Some rot under spare. The front end has been rebuilt. Has 4 speed manual transmission, shift on the column. The interior is decent with a few tears here and there. The car ran. Clutch and transmission are in good shape. Tires are like new but weather checked. Car has a current NYS inspection sticker. I have a transferable NYS registration in my name for sale. I cannot verify the listed mileage.