Thanks Everyone. The issue has been truly resolved.
The main problem was the fuel mixture was set too lean and because the car had no thermostat valve the carburettors automatic choke was set in such a way that it was working at its minimum.
So thermostat valve was installed and automatic choke was set properly and finally the air fuel mixture was adjusted. No problems in distributor were found, it was running fine. Now the car is running brilliantly, no startup issues, starts in cold or hot without pressing accelerator on one crank.
A big thanks to pakwheelers who helped, @Xulfiqar @capsat @ahsanonline .
A special thanks goes out to Hanif Bhatti bhai @Libra who shared the number of Mushir khan, who did all the job and without whom this will not have been possible.
So thanks to everyone again.