Impossible to do without clear, closeup photos. Seek the services of a professional appraiser.
$50-$100
Pi Squared
50-200 usd
The gun was an ivory-handled .44 Webley British Bulldog revolver.
10-150 usd
Could range from 100-10000 USD
$150
Jacqueline de Bellefort's revolver in Agatha Christie's Death on the Nile is described as small and pearl-handled. It is mentioned that she always carries it with her, tucked into her belt.
Avengers Did you know:Emma Peel's revolver on "The Avengers" is a gold-plated, pearl-handled pocket version of the Webley Mk IV.
I have seen these sold for 325.00 to 450.00 dollars generally if there is someone that will pay it it's because of sentimental value
With any one-of-a-kind item, the only way to determine the value is to sell it, and see what it brings. There is no "book value" established, since there is only one of those. The other issue is provenance- a chain of proof that THIS gun was HIS revolver. That will consist of documents, receipts, photographs, etc, and not merely word-of-mouth, Also, since he lived several years after the battle, the question of WHEN he acquired that revolver would arise. Any such sale would best be handled by one of the major auction houses that deal in collectable firearms.
You spelled it correctly: handled.