Blue Ridge, GA
Every homeowners policy I've had contained a multiplier value for for all contents based on the value of the home insured, like 2.5x. So in a full loss the number is known in advance - value of the house x 3.5. You need to make sure the value for the house is adjusted for your current value.
If your contents are more valuable than that then you need an additional rider. But this doesn't need to be specifically for pinball machines.
In the OP's original post, worried about a sump pump in the basement, flooding and water damage is a whole other story. Partial losses involving theft, water or wind are a PITA.
I'm not sure I'd worry about a single machine, and not sure you will ever find someone to go through the hassle of underwriting a policy for a single machine.
