Insuring guns is a lot like insuring cars, there is “book” value, “replacement” value and “collector” value.
Let’s take my 1977 Ranchero. Book Value is about $2,300, Replacement Value is about $15,000. Collector Value is about $5,000
Take my 1911A1 Colt GI issue .45 mfg’d in 1918. Book Value is about $900, Replacement Value is about $1,600. Collector Value is north of $20,000 due to the documentation I have of it and who it was carried by and where.
Insurance companies are in the business or praying that nothing happens to your stuff so you keep paying them for “nothing” and if something does they are in the business of giving you the least agreed upon amount. Hence they will “total” a car at the drop of the hat.
All that said I have better than good safes that stay locked. So barring a search warrant and a plasma cutter ain’t nobody but me getting inside and I don’t think my house can burn log enough or hot enough to cook what’s inside.