My own insurers stipulate valuations being done by a member of the National Association of Jewellers, if you use the search facility on their website to contact local members I'd imagine something could be arranged.
(My own valuation included collection and being brought back by the valuer, and all the watches being insured from the moment he signed for receipt of them).
https://www.naj.co.uk/advice/Valuations-Insurance
Having said that and with both watches being current pieces reasonably readily available (and I guess insured for RRP) I'd suggest offering them proof of purchase along with proof of current RRP might suffice....??