Vintage Cars: 1975 280s hesitates when accelerating, bosch spark plugs, vacuum hoses

Question
i just bought a 1975 280s Mercedes in mint cond i guess the guy never drove it im having a problem with when im stopped at a light or what ever i go to push on the gas and it will hesitate then go it also takes me a couple times to start it in the morning and now today i was leaving work it started fine i put it in reverse then when i put it in drive it stalls i did that 3 times. i put stuff in the gas tank that cleans the insides today then filled my tank so ill see if it cleans stuff out but i want to know if i should be doing something els?

Answer
First check that ignition timing is to spec. then look for all the
rotted vacuum hoses and replace them. Then replace the Bosch spark
plugs with NGK. If problem is still there check the throttle to
auto trans linkage.

Off the shelf chemicals are a waste of money. To absorb the accumulated
water, add a pint of isopropyl alcohol to the tank.

Use a tier one gasoline to remove carbon deposits on the valves.

If this does not fix it then the carb. needs looking at.

Get a Haynes manual for this very fine vehicle.