All good advice, one thing that no one has said is keep the record separate. My wife's dad had an ex walk off with his guns during a divorce. She moved out and took his guy stuff: Guns, tools, and anything that had value. Being I am my wives 3rd husband, I am leery to let her see my list of guns and there values. I got married at 37.
Funny story, my 7 year old great nephew is being all boy and likes guns. he asked how many I had, and true to my form, I did not give him a number. I responded not enough.
For that reason ,I have my list on my work computer. My list includes: make, model, serial number, cost, and value. I also have some pictures on my cell phone. I might want to make a flash drive with pictures and list.