Once the grant of probate had been obtained the solicitors had collected in all of your father assets in readiness for distributing his estate the estate accounts would have been prepared and sent to the main beneficiaries to be signed off.
That the solicitors have not retained the accounts with their papers is highly unfortunate and very unusual, though perhaps less surprising given that they were intervened by the SRA.
You should get in contact with your brother and ask to search through his papers, both you and he would (or should) have been sent the accounts towards the end of the administration. If your brother does not have them then you can try the other beneficiaries.
Getting hold of the final accounts if they are not with the papers held by the solicitors or with the other beneficiaries is problematic.
You could contact HMRC and make a request submitting evidence of your status as beneficiary and confirming your unsuccessful efforts to obtain them thus far. Forms confirming the size of the estate for IHT purposes would have been submitted along with fairly detailed schedules on the types and value of the assets in your father's estate would have had to have been submitted to them and they may still have copies of them
These are not the same as the final estate accounts obviously but in the circumstances it may be the next best thing. The size of the assets actually collected in may have changed after the initially submitting the forms and if so there should be a evidence of an adjustment of the assessment of the estate providing further details of the amended values.
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