Well spotted April.
In my opinion the will may have become invalid for several reasons. One of them is that the will had not been updated. It is important to update your will regular.
I honestly feel that the rules of intestacy applies in this case. In order to distribute the estate correctly.
This would mean that CC would inherit nothing, but could have applied for a discretionary payment form the estate.
It can get very complicated for the closest spur would only inherit the first £250.000 the rest of the estate would be divided up between the next in line and so forth.
Foe example say NB left £300.000 the first £250.000 would be divided up between the closest relatives thus being AP and JP the rest would then be divided up with the rest of the beneficiaries.
The estate would have gone to probate and the court would have legally decided who would inherit under the rules.
The will appears to have been made prior to 1982...I don't think anyone of us can say that the will was not distributed correctly because we don't know the correct circumstances. 
A will is only invalid if it was not executed properly. There is no need at all to ever update a will for it to remain valid.
I assume you intended to say the residuary bequeth in the will failed and thus that intestate rules apply because the will failed to dispose of all property of the estate.
If a will is properly drafted the only time you need to update it is if you want to add a new beneficiary or want to change things around in some other way including deleting a beneficiary.
If properly drafted itl will list enough alternate beneficiaries so that death doesn't require any changes and the only change could be a result of changing your mind. Some lawyers don't like that because then they lose future business but that is the ethical thing to do.
This is from the most recent will I drafted (I edited the names to initials to protect the people involved):
I give, devise, and bequeath all of the rest, residue, and remainder of my estate, of whatever kind and character, and wherever located, to my Spouse. If my Spouse predeceases me then my sons DJK and HJK shall inherit in equal shares. If either of my children predeceases my Spouse, his share shall pass to his issue in equal shares. If either of my children predeceases my Spouse and does not have any living issue to inherit his share, then his share shall go to his spouse. In the event either of my sons predeceases my Spouse and has no issue or spouse to inherit his share then my remaining son’s side shall inherit the entire remainder. If none of these beneficiaries survives me, then the rest and residue of my estate shall pass in equal amounts to the following charitable trusts;"
You can list as many alternative beneficiaries as you want. They decided to leave the money to charity instead of more extended family if their sons, grandchildren, great granchildren or the wives of their children are all dead. But you could list all the beneficiaries you want before finally listing a charity.
Instead of intestacy law kicking in they wanted it to go to Indian (India Indian) charities. I have no idea why they don't want it to go to siblings and cousins they did not say why not and I didn't ask snce it is not my place.
Note the complete absence of legalese (save for the word "issue"so that anyone reading it could understand it, that is the perferred method today so that those signing and wtinessing it can understand it as can any executor instead of needing legal help.
I have no idea if the UK has similarly gotten rid of the legalese or not in their modern wills but the principle is the same where you can list all the alternative beneficiares you want so that you never need a new will unless you want to remove/add a beneficiary or change amounts.
