Sale of foreign gift - Declare and Capital Gains query

My parents abroad have gifted me a valuable watch recently. I’m planning to sell it as I’d rather have the cash. It’ll now be sold as an ‘almost new’ item slightly under original market value. I expect it will sell for around £45,000. Questions I have are 1: Does this need to be declared as a self assessment to HMRC? I’m PAYE and don’t do a self assessment 2: How do I provide evidence of the original market value of the watch? Do I need the original receipts that my parents received when purchasing the watch? (Not really available)

Hi AfshaYK,
You may wish to review the guidance here:
Pay no import duties or VAT on inherited goods
To be sure there is nothing to declare.
Please have a look at the guidance on capital gain in personal possessions here:
Capital Gains Tax on personal possessions
And in particular the section in possessions with a limited lifespan.
Thank you.