I've admired IWC watches for years. I didn't know my father owned one and have unexpectedly inherited a beautiful Pilot Automatic Chronograph!

My father lived in Hong Kong and the watch, strap and box has suffered from the years of high humidity. I'll cherish this watch and owe it to my dad to look after it as best I can. I want to restore it to the best condition possible.
Excuse the newbie questions. All replies are much appreciated!
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[li]No doubt a IWC service would be the best available and I plan to get one done now at least, but what about in future? Should I even consider a service by anyone else?[/li]
[li]Are replacement IWC boxes available to buy? The original box is beyond saving due to years in the humidity.[/li]
[li]If I'm considering a valuation by IWC should I have the watch serviced and the strap replaced FIRST? i.e. Presumably the condition of the strap would affect a valuation?[/li]
[/ul]
Thanks everyone. I'm looking forward to learning more about my watch so I feel like a worthy owner!