• Survey number or land identities? Which is valid?

In 1943, My grand father(A) bought a land of extent 1.80 acres in his name from his self earned money. In 1947 the land was shared among with his 2 brothers(B,C) by a unregistered family memorandum. The land has 4 survey numbers (1,2,3,4) with 0.75 acre in 1 , 0.45 acre in 2, 0.37 acre in 3 and 0.23 acre in 4. The 3 brothers divided the land has 0.46(0.30 + 0.16) for A, 0.46(0.30+ 0.16) for B, 0.46(0.30 + 0.16) for C without mentioning which survey number goes to whom and also leaving the 0.42 acres unmentioned.

In 1949, C sells his part of share with survey number 1 ( 0.31 acre) and survey number 4 (0.17 acre) but showed the land identities of survey number 2 for that 0.17 acre. 

Earlier in 1947, C had mentioned in a leasing document that his share was 0.30 acre in survey number 1 and 0.16 in survey number 2.

In 1963, B also sells his share of 0.16 stating survey number 4, but showed the land identities of survey number 2.

In 1990,the first buyer from C sold the land(0.17) to another person but with survey number as 2 as shown by the land identities.

Later all the buyers and sellers deceased , the heirs of B and the heirs of first buyer from C occupied the survey number 4 stating their parents sale to others wont be valid. 

Survey number 2 is also occupied by the buyers, as they were shown the land identities of that land.

Please find below the queries I have, regarding the above dispute

1. What share does A gain from the unregistered family memorandum?
0.46 acre or 0.88 acre(0.46+ 0.42 )
(Note: 0.42 acre unmentioned in family memorandum, and property being in A's name.)

2.Which will be considered in selling of properties?
Whether survey number mentioned or identities mentioned?

3. Do B and C have the right to sell more than 0.46 acre?

4.If not so then, Can others property be sold by just having their signature in evidence column? 
(Note :C sells his share stating as 0.17 acre and 0.31 acre with A's signature in evidence column, while only 0.30 and 0.16 are mentioned in the family memorandum)

Please kindly clarify, which selling and occupying are valid, invalid and How should I proceed further?

Thanks in advance.