Wow. Sorry I won't be able to help you with advice, but I sympathise deeply with the situation. Its such a shame that we all (at some point) have to sort these legal/financial issues out, and are beholden to the systems (legal, tax and justice) whose sole aims seem to be to get their 'cut' first. Family just want a simple execution of the will, matching the stated wishes, and it all gets so mixed up.
It seems to be a nightmare to do it simply - only those with the financial clout to do so come out with the tax efficient solutions, and the lawyers get their cut regardless

I am so frustrated by the systems.