Memorandum Of Family Settlement is a valid instrument ?

Properties & Family Structure A Hindu joint undivided family consists of 3 sons of a deceased father. G1 is the elder son who is deceased & having 3 sons & a widow (P1, P2, P3, & P4) G2 is the middle son & he was acting as an Karta of HUF. G3 is the youngest son. They were enjoying all the properties of the deceased father of G1, G2 & G3 jointly. Now, in 1970 the youngest son (G3) wants to get himself separate from the family & hence he filed a partition suit case for claiming his share in all the moveable & immovable properties of the family. In 1973 the court ordered a Preliminary Decree that G3 has an equal 1/3 share in all the properties as scheduled in the partition suit & ordered to maintain an amicable settlement within 3 months & in default any of the parties in the suit can apply for a Final Decree on the same order. The Schedule of the properties found in the suit was : A – a two storied dwelling house B - a two storied dwelling house with tenants C - a two storied dwelling house with tenant. D - a vacant land. Upon agreed from all the members, it was decided that the partition in metres & bounds in all the properties was not feasible & hence they agreed to divide the properties among themselves rather than going for partition & executed an Unregistered Memorandum Of Family Settlement which was duly signed by all the 6 members along with an individual affidavit declaring a No Claim on the other property which has been allotted to the other member & the same was Notarized. The Division of the properties is as follows : Schedule property (A) was allotted to G2 Schedule property (B) was allotted to P1, P2, P3 & P4 sons & widow of deceased G1 Schedule property (C &D) was allotted to G3 Now, G2 on the basis of the Court Decree & the Memorandum Of Family Settlement made an Unregistered WILL of his property in 1981 declaring that the property (A) which he received through family settlement will be allotted to his grandson Ex1 (minor) though he was a minor his father & mother would act as an guardian until he is an adult & made his father & mother as an executor of his WILL along with him. My Questions : 1. Does an Unregistered Memorandum of Family Settlement deed is valid in the eyes of court ? 2. Does individual affidavits of no claims of other properties which is Notarized is valid in eyes of court ? 3. Can the Grandson of G2 get a Probate on the basis of the WILL. ? 4. Can grandson execute the WILL as he is also an executor in the WILL & he is an adult person now ? 5. What is the process to grant a Probate in this case ? 6. As the witnesses in the WILL are all expired is there any problem arises ? 7. What are the documents required to take a Probate ?