M38A1 started to run very rough with misfires

[Blaise]

When I acquired my M38A1 I had to replace the blinded 24v spark plug cables as it was running on 3ish cylinders.
It then run well for approx 50 mi and started to run rough. Replaced the condensator and it run well for approx 100mi.
Then suddenly started again to run very bad. Almost no power, misfires and coughing.
Points have been set to 0.02", the gap was too big.
Running better but still bad.
My mechanic set the Dwell at 40 instead of 42...
I have massive rust pieces in the gas tank.
Next is to replace again the condensator and replace the igintion coil as well.
Do I have a tension issue that damages condensators one after the one?
Should I check for air leaks in the carb?
Thanks