I recall having a similar issue some years ago.
On the basis that a bank account consists of cash, the Nat West investment account, whilst held with a bank, is not a “bank account”.
The Legal & General account might also be outside of the definition.
Similarly, I recall a cash ISA is not a “bank account”.
As regards the other accounts, it may depend on what they really are. If cheque/current accounts, I would expect them to be within the definition, as I anticipate would be a deposit or regular savings account. However, if any are bonds, or other similar forms of investment, I feel they would be outside of the definition.
Mindful that some are of significant value, I suggest it would be appropriate to seek advice of Chancery counsel, who should also be supplied with a copy of the will instructions, if still available.
Paul Saunders