Division of estate

My father purchased a plot from Improvement Trust Amritsar in the year 1972 out of the savings given to parents out of salary earning of the elder brother who was in Government Jobs since 16/8/1965 and there after completed construction of the plot in the year 1972 that too out of salary earnings of the elder brother and the total family( parents 2members& brothers 3 sisters 2) started staying. All the Brothers and sisters were younger in age to the eldest brothers. Eldest brother 1947 Born Younger Brother 1956 Born youngest Brother 1960 Born. The sisters are married. The father left a will showing his will that after his death wife will be owner till her life and after her death all the brothers will get equal share. Nothing will be payable to sisters.(daughters of deceased parents as mentioned in the will ) Now the younger brothers are not keen to share the property and say that they are not going to share anything more than the share mentioned in the will. Though the Eldest Brother is saying that since his entire salary etc., was used in construction and purchase of plot hence he should be given some higher share. Every body in the family is well aware of the contribution of the Eldest brother. But there is NO documentary evidence to show that the funds utilized by the father for the purchase of plot and construction was given by the elder brother and in those times 1956-1972 the salary was given in cash by the concerned department and cash was given to parents every month. Both the younger brother are now well off financially and the financial position /assets of the Eldest Brother are much less as compared to the younger brothers. The original sale deed and original will is in the custody of younger brothers. Intqual in the revenue record is not recorded in the name father a it was purchased from Govt improvement trust hence this fact of intqal did not strike. After the death of both father and mother intqal is to be got done in the name of three brothers, which can be done on the basis of registered will and other documents. Death certificates of the both father and mother is available with the brothers. Please clarify how higher share can be claimed from brothers and if there any possiblity of getting the intqal in the name of two brothers without my knowledge and selling the same without my consent, if there is any chance then how to protect the interest.