I revisited insurance coverage on the hifi and record collection when I moved from NY to Texas at the very beginning of 2017. DOT insurance is by gross weight and a joke. I was covered by Chubb, which I started using years ago- they insured various exotic cars I had for less than what they charged for a daily driver.
I have riders for the hi-fi, the records, and some other high value stuff. A year or more ago, we finally parted ways with Chubb- though I thought they were very good--their premiums got crazy. We switched to a company called "Pure" which writes for high value assets. Hopefully it is never going to be an issue.