As for speaking to the NHS pensions directly - to be honest, unless I put this in writing, I don't hold out much hope of addressing the question.
Having played a frustrating game of "call centre bingo" with them earlier today to try to confirm if my brother did actually make an expression of wish, I think if I did manage to get through to "an expert" that would probably be the chap that know how to access the guide mentioned above, who would religiously quote the relevant section and probably not 'get' the nuance of the question I am asking. No offence to call centre staff, they are are there to do a job, but oftentimes the escalation path when things are beyond their remit are pretty poor.
Anyway I have thought further through CK's response and what the extra guidance I found says and would position it like this :
1. Had my brother specifically nominated that my mother should be the recipient of this 'benefit' - then they would write a cheque for the amount in question to my mother - without any suggestion that it is deemed to pass through my brother's estate.
However, I suspect we are at :
2. If my has not made a specific nomination - then they would write a cheque for the amount in question to my mother - but this time suggesting that the amount is deemed to pass through my brother's estate.
That seems illogical to me and I wonder it is even there 'call' to make? In both cases they are writing the same cheque to the same person.
Anyway going back to CK's very useful input suggesting that even in case 2 the money may not go through the estate.
The main reason given for this was that the scheme has discretion as to whom they pay the benefit. I'm not sure in fact if this is invalidated by the later information I gave - that the guidance notes say this is not a discretionary scheme.
Going back to CK's final suggestion :
I would therefore strongly recommend that you speak to the company involved and clarify 100% that the benefits do not and will not form part of the estate irrespective of how they decide to distribute it. And if so, ask them to confirm it in writing.
I initially took this as a suggestion to ask them an open question, but I wonder now whether it would be more appropriate to make it a statement which we ask them to confirm?
I would like to give my solicitor some 'suggestions' as to how we might proceed - no offence to the solicitor I met earlier, but if CK cannot unequivocally answer this question - then I'm pretty sure he won't be able to either.
To be honest this area of doubt is probably the main reason why I have decided to be represented.
If I were judging the situation for myself I would be inclined to (ignorantly) judge that my interpretation that the money does not pass through the estate and therefore inform the creditors that my brother's estate was insolvent (to the extent of having no prospect of even covering the funeral and administration) and that no payments whatsoever will be available to them and see what they do.
I'm not sure that would be a 'wise' move on my part though!
(And just as footnote on that if I come across as a "rogue" in this sense - I posted earlier in this thread on my concern about how 'responsible' the primary creditor has been and that somewhat shapes my desire to scrap for every penny here)
Thanks again for the sympathies and help everyone (but mostly CK) - this is much appreciated.