That's interesting HuwG. My sister recently received a legacy from the deceased maiden aunt of her late husband. The difficulty was, the legacy was in the form of interest from invested shares. The shares were supposed to be left and not dissolved. She had to obtain a Deed of Variation, signed by all the other legatees, in order to cash in the shares and realise the principal.
It took ages and pots of money for the law firm involved. But finally she succeeded.
The aunt had been very close to my sister, especially after her husband died leaving her with two young babies. She spent every Christmas with my sister and supported her emotionally for years.
I'm sure she wouldn't have wanted all that palaver with her Will.