I have this forum as proof of ownership, plus 1000's of pics on photobucket. My insurance company is well aware of my hobby and I have up'd my content ins. a few times in recent yrs... my contents are actually worth more than my house, so I had to up the value of the house to keep both comparable, my ins co said.
I'm building a steel building garage this summer, looking forward to moving most of my hobby in there where it will be virtually fire proof! b/c probably half of it isn't readily replaceable. I didn't place much value on my time for building any of it, just guesstimated replacement cost of kits & parts.
Communicate with your ins co, let them know what you have & what you want to insure it for and pay the premium for piece of mind. I've already had one house burn to the ground with 20yrs worth of memorabilia gone forever. Filling out the proof of loss forms, I then realized I was about 30% short on my coverage! (lost a 355 blown small block rated for 600hp, everything brand new or fully machined, Muncie 4spd, numerous other Chevelle parts, ect killed that project car build!)

I hope it never happens again, but I'm well covered this time.