Hello and welcome, William! My name is Doris.
I have been an antiques collector, dealer and appraiser for over 56 years.
I will be pleased to help you.
Your photo was made/signed in the first year of the reign of George VI - 1937. Edward, Duke of Windsor, abdicated that year.
This special year makes the photo and its signatures more valuable. My research indicates it, if verified, would have an estimated retail value of $2200-2400 assuming good condition and depending on sale geographic location.
Collectors will want the signatures officially verified by an independent agency to realize this significant retail price.
See the following image for the name of a service in England that verifies signatures.
In general, a private seller to a dealer, via consignment or at auction can expect 30-50% of estimated retail value.
Insurance replacement values are usually about 10% more than retail values.
I hope I have helped you.
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