Thanks Lee. That is very helpful.
The other problem I have is that the value of the shares in question are worth less than the cost of administering the process to comply with getting a Medallion Signature Guarantee stamp provided by an eligible institution.
So in this case I perhaps will have to recommend abandonment of the assets.
Its a pity the US processes are not as user friendly as the UK processes.
However the information will be very useful in the future for higher value estates.
Thanks again.