Thanks for the Royal London link - I’ve also reconfirmed the position with
which also sets out further options.
So basically one has to chase from HMRC about 45% tax which will be deducted from the pension pot after the 25% tax free allowance by HMRC - unless quite a small pot. Good to know. Maybe one can use the pension forms they refer to to claim in the meantime though a large withdrawal will probably prove fairly accurate.