General: successions: death of sole trader
When a sole trader dies the business may pass to the surviving spouse or civil partner. If so assessments may be made on the surviving spouse or civil partner as if the trade carried on by the sole trader had not ceased (see BIM80570).
Whether or not assessments are made on the surviving spouse or civil partner on a continuation basis (that is, as if the trade had not ceased) capital allowances should be calculated as if the assets had passed from the sole trader to the surviving spouse or civil partner at open market value.
You should accept the figure adopted for probate purposes as open market value.