Remember at Bapuji's funeral Manoj noticed that he only had 5 fingers on each hand when Bapuji had 6 fingers on one of his hands?? If they really wanted to know whether it was Dhansukh or Mansukh, why don't they just look at his hand???
and another thing-
When Mansukh was telling Daya all about his past, how come he never mentioned a twin brother?? He said that all he had for comfort was Sharda. Where in the world was his twin brother???
And also, if they really want to know whether this is Mansukh or Dhansukh, why don't they try to find the real Dhansukh??? Do they even care if he is living or dead????