I'm no insurance expert, but this is my understanding after doing a bunch of research on it about 10 years ago. It all depends on what insurance you have, the value of your collection, and how much of it has "collectible" value above and beyond normal retail.
I determined that I do not need extra insurance as your normal household insurance default assigns something like 40% of the home's value to your possessions. You can always increase this if necessary. Let's just round numbers. Assuming your house replacement value is $400k, your possessions are insured for $160k. I know my couches, chairs, beds, and SW stuff probably wouldn't exceed that value. However I don't have anything particularly rare in my collection. I'm fairly convinced I could replace most of my collection for less than what I originally bought it for.
The one challenge is that when you have "rare/collectible" items - like all your vintage stuff - that was originally $2 in the store and is now worth $125, your insurance won't generally cover that "collectible" value. I know you've got a ton of nice stuff that falls in to that category.
As I recall you would need to get your collection documented/appraised and generally get a rider on your insurance that would cover these collectible items. Depending on the coverage, it may or may not be all that much.
Give your insurance agent a call. They'll walk you through the whole thing. As I recall it can vary from company to company and it may be worth your while to change insurance providers based on what collectibles coverage you need.
If you haven't already purchased a backup battery for your sump pump, I would do that first.