Before you do anything major you should adjust the valves and maybe change the oil. I just got another 230S which had compression from 105-145. After I adjusted the valves I've got 135 on all cylinders. A little Marvel Mystery oil can help loosen up any sticky rings. Before you pull the head you should do a cylinder leakage test. The carbs on your car are Zenith 35/40 INAT. They are very complex and difficult to get right. They can dump gas into the cylinders like crazy. You can try to syncronize them with a Unisyn but rebuilds may be in order. Good luck.