What is the ruling of Sharia on the inheritance of the paternal aunt that was relinquished 30 years ago, which she is now demanding to restore, despite the waiver being documented with a trust receipt that was not cashed, and the rest of the inheritance having been divided among the heirs by mutual consent?

If an agreement was reached on the division of the inheritance and your paternal aunt accepted her share (1000 pounds), then this division cannot be revoked, especially if it was officially registered. This is because division is a binding contract, unless there is an impediment such as clear overreaching (ghabn), a defect, or a claim of entitlement. Clear overreaching is excluded here due to the long period of your aunt's silence and the registration of the contracts.

However, given the change in currency value and its depreciation, she should be compensated for this depreciation. If she did not claim the money during these years, a reconciliation should be made regarding the compensation. But if she did claim it and was procrastinated with, then compensation is obligatory. The compensation is calculated by determining what 1000 pounds was worth in gold or dollars at that time, and then she is given the equivalent of that value now.