I have my Bronco on my regular auto insurance policy (Allstate in my case). I (ab)use it as a daily driver, so collector car insurance seems like it would be problematic.
Also I only have liability on it. A long time ago I was let in on a little secret: Insurance companies try to turn a profit, and are actually pretty good at it. So on average you'll come out ahead if you don't insure things. Yes, there are some things you can't afford to lose, so you need to insure them: your house, liability against a law suit, medical costs, maybe your car, maybe some others (this wasn't meant to be an exhaustive list). But a toy is something I can afford to lose.