Decree 1961 validity null and void and already satisfied?

Decree of specific performance for a land of 42 bigha and 16 biswa in the year 1961, and decree holder got the sale deed in his favour in year 1978 after depositing the amount decided by court, despite of the fact that earlier to sale deed high court delhi one division bench wrote in his order that the decree 1961 is erroneous and a blunder but no party has pointed out the error in decree so we are with no option but to confirm and allow the decree 1961. Sir the above sale deed through court1978 was done in after the submission of the draft sale deed from decree holder for more than 54 bighas of land. Now in the guise of sale deed through court decree holder obtained more than 50 bighas of land and sold that land to various persons. Now he is claiming for another 3 bighas of land where already 32 families are staying and 32 houses are also there and these houses are constructed on lands purchased through registered sale deed in year 1971 from the coloniser with a lay out plan. Now we some families in the year 2006 came to know about the fraud through various documents like will and other revenue record that decree holder already obtained more than 42 bigha 16 biswas of land , currently we challenged the decree 1961 to be null and void and already satisfied and not applicable to usand fraud from the decree holder , case is district civil court. Please tell your views about decree 1961 and if it is null and void.