You will recall that Marco Carvalho died in a skiing accident in December 2023. Marco's estate comprises the following assets, all of which are held in Marco's sole name unless otherwise stated:

Callow Meadows (owned jointly with his brother Antonio) £250,000 (value of Marco's share)
Savings £400,000
Classic motorbikes in showroom £750,000
Harley Davidson motorbike £20,000
Small holding shares in various quoted companies £50,000

Callow Meadows was inherited by Marco and his brother Antonio following the death of their grandfather in 2008. They owned Callow Meadows as beneficial joint tenants. Since the divorce, Marco had been living at this property. Six months before Marco died, he realised his dream to acquire and run his own business working as a sole trader dealing in classic motorbikes. Marco was a motorbike enthusiast and used the Harley Davidson motorbike for his personal use. You MUST attempt all parts of this question.

(a) Explain whether the will made in August 2023 was valid and whether it has since been revoked.